Diseases

Breathing Easy: Protecting Livestock from Respiratory Disease

Mon, 22 Dec 2025 17:47:19 GMT

Keeping livestock healthy can feel like a delicate balancing act, and winter weather makes that even harder. Cold fronts, sudden temperature swings, and damp conditions can weaken animals’ immune systems, making them more vulnerable to respiratory illnesses like pneumonia.

Dr. Kevin Washburn, a professor at the Texas A&M College of Veterinary Medicine and Biomedical Sciences, explains what causes pneumonia, how to recognize it, and how to keep animals healthy during the cold winter months.

Clearing the Air on Pneumonia

Pneumonia is a common and serious respiratory illness that can be caused when certain viruses or bacteria infect the lungs. The condition leads to inflammation, fluid buildup, and lung damage, making it difficult for animals to breathe.

“Most of the bacteria that cause pneumonia live in the animal’s sinuses without causing disease until their immune system weakens,” Washburn says. “When the immune system weakens, the bacteria can be inhaled into the lungs and are able to multiply and cause damage.”

Stress is one of the main factors that can weaken an animal’s defenses, enabling bacteria to reach the lungs and cause disease.

Common stressors include:

Transportation over long distances (also known as shipping fever)
A viral infection
Weaning
Severe weather changes
A new environment
Mixing with calves of different ages at an auction
A change in feed
Introduction of new animals to the herd

More than Meets the Nose

Pneumonia often begins quietly but can progress rapidly, sometimes within hours. Detecting the early signs can significantly improve an animal’s chances of recovery.

“Loss of appetite is one of the very first signs of pneumonia,” Washburn said. “This is accompanied by an increased respiratory rate and elevated temperature.”

As pneumonia progresses, animals may exhibit changes in posture and breathing.

“The animal may stand with its neck outstretched and its elbows flared out. This is often accompanied by an increased effort to blow air out of its lungs while breathing,” Washburn says. “Sometimes, the animals may ‘grunt’ as they exhale because they are forcibly pushing air out.”

In severe cases, animals often alter the way they breathe even more.

“The animals may start to open-mouth breathe — this is a severe sign indicating the animal can’t get enough oxygen and may be near death,” Washburn explains. “Farm animals are obligate nose breathers, meaning they normally only breathe through their nostrils. When these animals open their mouths to breathe, it indicates that they are desperate for normal breaths.”

Recognizing and responding to these signs early helps prevent spread of disease and improves treatment success. If you notice any of these symptoms, contact your local veterinarian to plan the next steps for your animal.

Prevention Is in the Air

Air flow is an important part of preventing disease, so owners should be aware of ventilation needs when bringing animals into barns for the winter.

“Poor air circulation leaves the animals breathing in more of the same air as their surrounding herd or flock mates, leading to viruses being easily transmitted through aerosol droplets from the lungs,” Washburn says. “Stagnant air allows this to happen more easily, as moving air would typically sweep these droplets away before they can reach a nearby animal.”

Another way to help reduce the risk of pneumonia is to vaccinate.

“Like all forms of respiratory diseases, vaccination is the most important tool in prevention,” Washburn says. “There are vaccines for all the common bacteria and viruses that cause or lead to the development of pneumonia in all species of farm animals.”

Planning ahead can also help protect animals during travel or when they come into contact with unfamiliar livestock.

“In addition to a regular vaccination schedule for all animals, those that are going to undergo transportation for exhibition should be given booster vaccinations three weeks prior to their event,” Washburn says. “Avoiding nose-to-nose contact with other animals as much as possible can also aid in prevention of disease either on-site or when the animals return home.”

Another consideration is when you are weaning young animals in the spring.

“Weaning is a very stressful event for all farm animals,” Washburn says. “Vaccination three weeks prior to weaning and again at weaning can aid in the prevention of pneumonia.”

With proper preparation — including good ventilation, vaccination and stress reduction — owners can lower the risk of winter pneumonia. By understanding its causes and recognizing early signs, you can help keep animals healthy throughout the coldest months of the year.

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5 Livestock Diseases That Could Impact U.S. Food Security and Economic Stability

Thu, 11 Dec 2025 20:45:01 GMT

Production animal disease outbreaks are not only animal health events but threats to economic stability and food security. A new report from The Farm Journal Foundation , The Mean Sixteen: Biosecurity Threats Facing U.S. Agriculture, estimates the collective annual costs to U.S. agriculture due to outbreaks of the top five livestock diseases could top $300 billion without proper preparation.

“It is absolutely crucial that the U.S. should support mechanisms to protect farmers from risks and make sure that our food supply chain can remain resilient even when challenges occur,” wrote Stephanie Mercier, senior policy adviser at Farm Journal Foundation.

Mercier identifies five diseases with the potential to disrupt U.S. livestock production, trade and response infrastructure at scale. These include foreign animal diseases as well as ongoing threats:

Foot-and-mouth disease (FMD)
African swine fever (ASF)
New World screwworm (NWS)
Highly pathogenic avian influenza (HPAI)
Porcine reproductive and respiratory syndrome (PRRS)

Foot-and-Mouth Disease: Trade-Stopping Risk to U.S. Livestock

Foot-and-mouth disease, an infectious and sometimes fatal viral disease affecting a range of ungulates, remains one of the highest-impact foreign animal disease threats to U.S. agriculture. While the U.S., Canada, and Mexico are classified as FMD-free, outbreaks in Taiwan (1997), the United Kingdom (2001), and this year in Germany and Hungary, represent how relevant this disease remains as both an animal health and economic threat.

Modern production systems characterized by high animal density and frequent interstate movement would complicate containment efforts in case of an outbreak. In 2015, a report from Kansas State University found an FMD outbreak beginning in a U.S. state with high populations of vulnerable livestock could cost nearly $200 billion to the U.S. economy if no emergency vaccine program was implemented.

A 2018 provision to the farm bill mandated the establishment of an animal vaccine bank; FMD was chosen as the first disease for vaccine stockpile. While FMD vaccines reduce an animal’s chance of being infected, they are generally not administerd in FMD-free regions as it is difficult to distinguish between vaccinated and FMD-infected animals in a clinical setting. Further, World Organization for Animal Health (WOAH) protocols allow for trade bans to be imposed on countries using these vaccines.

African Swine Fever: Persistent Threat to U.S. Pork Production

African swine fever has expanded globally over the past decade and remains one of the most significant threats to the U.S. swine industry causing hemorrhagic fever with high mortality rates. In 2018, a massive ASF outbreak in China resulted in the loss of half of the country’s swine herd, approximately 225 million animals, and cost the country’s economy around $111 billion. Since then, ASF cases have been reported in countries across much of Asia and Europe .

(Farm Journal Foundation)

It has been estimated an ASF outbreak in the U.S. would cost the economy nearly $80 billion, due to loss of exports and reduced industry revenue, but could also affect the crop sector due to decreased feed demand. The extensive feral hog population across much of the country would further complicate containment efforts.

There is no globally available ASF vaccine; however, in May 2025, the WOAH adopted their first international standard for ASF vaccines . This was followed by the release of field evaluation and post-vaccination monitoring standards in July.

New World Screwworm: Reintroduction Risk and Surveillance Dependence

The NWS fly lays eggs in an animal’s skin, often at wound sites, and the hatched larvae burrow into the animal, consuming the flesh. Prior to 2025, NWS had been largely absent in the Western Hemisphere north of Panama; however, since the beginning of the year, outbreaks have been creeping northward, with most recent detection being just 120 miles south of the U.S.-Mexico border.

The USDA estimates that if NWS were to cross the border into Texas, it could cost the state’s economy at least $1.8 billion while putting the rest of the U.S. beef sector at risk. In an effort to tackle this threat, the USDA announced a five-pronged plan to combat the pest including sterile fly production, closing of the U.S.-Mexico border to cattle trade and increased communication with state animal health officials.

The same sterile male fly technique that eradicated the pest in the U.S in 1966 is being applied for the current outbreak, with sterile fly production facilities open in Tampico, Mexico and opening in Edinburg, Texas .

While no NWS cases have been detected in the U.S. yet, the fly is still having an impact on the economy. With the U.S.-Mexico border closed to cattle imports , the already reduced U.S. cattle herd could shrink even further. With strong demand supporting U.S. beef prices, Omaha Steaks CEO Nate Rempe predicts ground beef prices could reach $10 per pound by the third quarter of 2026.

(Farm Journal Foundation)

Highly Pathogenic Avian Influenza: An Ongoing Multispecies Challenge

Highly pathogenic avian influenza remains an evolving threat to U.S. animal agriculture. Twice in the past decade, major outbreaks in the U.S. have devastated poultry operations with losses of over 50 million commercial birds from 2014 to 2015. The latest HPAI outbreak began in 2022 and has since been detected in flocks in all 50 states resulting in an estimated loss of 169 million birds as of April 2025.

(Farm Journal Foundation)

HPAI is a zoonotic disease with reported infections in humans, hogs, cats and dogs. In March 2024, HPAI was detected in dairy herds in Texas and Kansas. Since then, HPAI outbreaks have been confirmed in over 300 dairy herds across the U.S. in 14 different states.

The 2014 to 2015 HPAI outbreak is estimated to have cost U.S. agriculture over $1 billion when accounting for losses to both the poultry and animal feed sectors, as well as losses in land value. Both this outbreak and the subsequent 2024-25 outbreak caused significant spikes in egg prices, with March 2025 prices rising to 350% of those of the previous year. U.S. milk prices have not yet been affected by the outbreak.

(Farm Journal Foundation)

Porcine Reproductive and Respiratory Syndrome: Endemic Disease, National Cost

The infection of hogs by PRRS has had a significant impact on the U.S. pork industry. First detected in the U.S. in 1987, PRRS infection causes pregnancy loss in sows and respiratory problems in pigs of all ages leading to poor performance. Unlike other animal diseases, PRRS infection can go undetected until issues with pregnant sows occur.

Analysis from Iowa State University shows PRRS caused an estimated $1.2 billion per year in lost production in the U.S. swine industry from 2016 to 2020. This marks an 80% increase over numbers reported a decade earlier.

With no cure at present, disease impact is minimized through biosecurity practices, vaccinations and management of infection with antibiotics. In April 2025, FDA granted PIC approval for the gene edit used in its PRRS-resistant pig. This technology could have a large impact on animal welfare, production costs and pork prices if adopted, though any impact is likely many years out.

Policy and Preparedness Implications for U.S. Animal Health

Across these diseases, the report identifies recurring gaps in U.S. animal health preparedness that extend beyond individual pathogens and suggests some key policy and infrastructure needs to help mitigate these threat risks:

Improved national biosecurity coordination including culling guidelines
Training for veterinarians for outbreak identification and reporting
Support for vaccine stockpiling programs and prioritized regulatory approvals for prevention and treatment products
Increased research support for both international collaboration and domestic work on biological control techniques of pests and pathogens, and disease-resistant genetic traits

“Investing in agricultural research, development and the long-term viability of our food supply chain is critical for protecting our national security and economy, and we are hopeful that our nation’s leaders will rise to meet this challenge before it’s too late,” Mercier writes.

The Farm Journal Foundation is a farmer-centered, non-profit, nonpartisan organization, created by Farm Journal in 2010, working to advance agriculture innovation, food and nutrition security, conservation and rural economic development.

When Cattle Don't Roam: Uncovering Tick Refuges with GPS, GIS and Modeling

Mon, 08 Dec 2025 20:00:46 GMT

Cattle fever ticks persist in South Texas not because eradication efforts have failed everywhere, but because, in some places, cattle never go at all. New research from Texas A&M combining GPS collar data, habitat mapping and individual-based simulation models shows areas rarely visited by treated cattle can function as ecological refuges for ticks, allowing populations to survive long enough to reinfest herds.

For more than a century, eradication programs targeting Rhipicephalus microplus have relied on a straightforward premise: treat cattle, interrupt the tick life cycle, and the population collapses. That approach nearly succeeded nationwide by the mid-20^th century, protecting the U.S. cattle industry from bovine babesiosis, a disease transmitted by the tick. However, in South Texas, particularly at the wildlife-livestock interface, ticks continue to persist despite regular treatment programs.

According to a pair of recent studies from Texas A&M AgriLife researchers, the missing piece might not be chemical efficacy or compliance, but behavior. Specifically, where cattle choose not to roam.

What GPS Tracking Reveals About Cattle Behavior

In the first study , cattle were outfitted with GPS collars to record fine-scale movement across the Texas coastal landscape known to harbor cattle fever ticks. Over extended periods, the researchers tracked when and where animals grazed, rested and avoided, generating a high-resolution picture of habitat use across seasons.

The results revealed that cattle did not use the landscape evenly. Instead, grazing and movement was clustered in specific habitat types while large portions of the pasture, particularly dense brush and shrub-dominated areas favorable to tick survival, remained consistently underused. Seasonal heat stress further amplified this pattern, shifting cattle away from certain habitats for prolonged periods.

These underused areas represent more than idle land. From a tick’s perspective, they are zones where pesticide exposure is low or nonexistent. Even when cattle on the ranch are treated, ticks located in places cattle rarely enter might escape control entirely.

By overlaying GPS movement data with geographic information system (GIS) habitat classifications, researchers were able to spatially define where these behavioral gaps occurred, effectively mapping where cattle presence, and therefore tick control pressure, was weakest.

The Role of Cattle Behavior Models for Predicting Tick Persistence

In the second study , researchers moved from observation to prediction. Using the acquired GPS-derived habitat use data, they built a specially explicit, individual based simulation model to explore how tick populations respond to different host and treatment scenarios.

Unlike traditional models that assume uniform host movement, this framework explicitly incorporates cattle behavior, including their avoidance of specific habitat types, alongside tick life history, habitat suitability and the presence of wildlife hosts, such as white-tailed deer and nilgai.

The simulations tested multiple scenarios: cattle-only systems, mixed wildlife-cattle systems, different pesticide treatment strategies and varying habitat use patterns. Across scenarios, a consistent result emerged. When cattle alone were treated, the standard eradication approach, tick populations frequently persisted in landscapes where cattle avoided substantial portions of tick-suitable habitat.

These persistence zones functioned as refugia: small but stable patches where ticks could survive, reproduce and later recolonize treatment areas. Importantly, the model showed eradication success was strongly influenced not just by those species, but by where hosts traveled across the landscape. Assuming homogeneous grazing behavior significantly overestimated the likelihood of tick elimination.

Why Cattle-Only Tick Control Fails: The Impact of Wildlife and Refugia

The presence of wildlife further compounded the problem. In simulated landscapes shared with deer or nilgai, ticks could cycle through hosts that moved freely through refugia, bypassing treating cattle altogether. Even low densities of wildlife were sufficient to sustain tick populations in favorable habitat patches, especially when cattle presence was inconsistent.

The modeling suggests eradication efforts falter not because ticks are ubiquitous, but because they are spatially selective. They exploit ecological and behavioral gaps. These gaps persist unless control strategies account for where cattle do not go.

Crucially, this research showed changes in grazing behavior, such as increasing cattle access to underused habitats, could substantially reduce tick persistence in simulation. Likewise, scenarios that incorporated treatment or management of wildlife hosts dramatically improved eradication outcomes.

A Spatial Approach to Tick Eradication

Together, the two studies argue for a reframing of tick eradication as a spatial and behavioral challenge rather than a purely chemical one. The failure to eliminate cattle fever ticks in Texas might stem less from insufficient treatment and more from incomplete coverage driven by cattle movement patterns.

This insight has immediate implications. Mapping cattle behavior using GPS data allows managers to identify where control pressure is weakest and to target interventions accordingly. This could be through adjusted grazing plans, focused surveillance, habitat modification or strategic wildlife management.

It all underscores the value of location intelligence in veterinary epidemiology. By integrating GPS tracking, GIS habitat data and individual based modeling, researchers can move beyond reactive control toward predictive, landscape-level strategies that anticipate where persistence is most likely. This reframes eradication not as a question of how much treatment is applied but of whether interventions reach the places cattle do not.

How to Manage Coccidiosis Risk in Weaned Calves: What Producers Need to Know

Mon, 08 Dec 2025 12:00:10 GMT

A ranch weans four groups of calves, all from separate pastures and breeding groups. They are placed in the same drylot to be fed, and three weeks later, some calves are dealing with bloody diarrhea. With the time of year and situation described, coccidiosis is high on the list of possible issues.

In the most recent episode of the “ Bovine Science with BCI ” podcast, Kansas State University veterinarians Bob Larson and Brad White look at this case of potential coccidiosis in weaned calves.

Larson explains there are other issues that can cause bloody diarrhea, like Salmonella or any other intestinal disease that cause damage to the intestinal lining.

One of the first factors to investigate is feed rations. In this case, these calves were being fed a corn, corn-gluten and soy hull mix with free-choice hay. Larson explains this is a rather fibrous diet with less starch, therefore acidosis and other related digestive tract issues can be eliminated.

The Prognosis

Studying the feces is another way to analyze the situation. Typical signs of acidosis include runny feces, sometimes containing gas bubbles, according to Larson. But he also adds that this is never a perfect test and to keep your options open when determining the prognosis.

To further understand feces tests, Larson explains that frank blood, often appearing bright red in color, indicates the damaged gut is further back in the digestive tract and the blood hasn’t been digested. When the blood is digested, like with abomasum ulcers or earlier tract issues, it appears black in color with a tar-like texture. In this ranch’s case, calves are presenting frank blood.

For more diagnostics, Larson says fecal floats are an option. There are different types of coccidia organisms that infect cattle in varying strengths. He warns these protozoa of the coccidia organisms will invade into the cells that line the intestine and then destroy the intestine as they multiply. But sometimes these protozoa do not show up in a fecal float, so it is important to not rule out coccidiosis if that is what is suspected, and the fecal float is negative.

White adds most calves will have coccidia organisms in their systems already.

Larson explains it is common for most mammals to have these organisms present in their systems, and the coccidia are specific to animal species. So, a high number of these organisms would confidently indicate coccidiosis, but smaller numbers should not be looked over either.

Larson and White both agree coccidiosis seems to be the issue with this ranch’s case, so the next item to address is where or how the calves contract it.

Control and Prevention

“They had it themselves — it’s not that they got it from somebody else necessarily,” Larson explains.

But he notes cattle can still get sick if they encounter calves carrying a coccidia species they haven’t been exposed to.

Young cattle like these are more susceptible to coccidia protozoa because they haven’t had time to build an immunity to them like older cattle would. However, there are a variety of populations of coccidia, so they cannot build an immunity to all types.

“There’s some challenges there keeping everybody on track nutritionally, and I’m mixing cattle from different sources, which probably means they are bringing in different types of coccidia,” Larson says.

White adds coccidia can be spread by fecal or oral contamination, and this setting is ideal for it. However, he also mentions their ration has an ionophore in it that should help control the contamination.

Rumensin or Bovitech are common ionophore products that provide control, but Larson says we should think of them as ways to control the multiplication of organisms. If cattle are at high levels of protozoa already, these additives are ineffective. But they are a crucial part of control and prevention.

For early precautions, Larson recommends feeding ionophore products like Decoquinate or Amprolium as they, “will do a better job of killing those organisms at other stages in the life cycle.”

Once calves are settled from weaning and their stress levels decrease, then they can be switched to other ionophores in their daily rations.

Larson says these treatments can be administered in feed or water, but it is often better to treat individual animals. Then, the whole group can be started on the ionophores for further prevention.

Managing environments and their conditions and limiting nutritional and weaning stress is also beneficial in the prevention of coccidiosis.

Larson reminds producers: “It takes consistent attention to the details to try to keep these problems at bay.”

Seeing the Whole Elephant: Systems Thinking and Animal Health

Mon, 24 Nov 2025 22:19:51 GMT

We all know the ancient parable of the blind men and the elephant: each man touches a different part of the elephant and becomes convinced he knows the whole animal. One feels the trunk and declares it a snake, another the leg and insists it’s a tree. Each observation is accurate, but each conclusion is deeply incomplete.

Veterinary medicine often falls into the same trap, not because of a lack of care but because of training to look closely. In a world where disease emerges from the interactions of nutrition, immunity, environment, behavior and management, the old parable reminds us the truth isn’t found in any single part. It’s found in the relationships between them.

Why Looking Closely Isn’t Enough

Pattern recognition is one of our greatest strengths. You learn to see classic presentations and link them with a diagnosis. For example, ketosis in a fresh cow or BRD in a calf with a cough.

But disease rarely lives in one organ system or one management practice. A narrow focus can deceive us. We might fixate on the ‘tusk’ because it looks sharp and obvious, while missing the constellation of forces actually driving the animal’s response.

Examples crop up everywhere:

A dairy lameness problem blamed solely on digital dermatitis, when the root cause is chronic wet bedding, poor ventilation and subtle changes in stocking density.
A calf barn respiratory outbreak attributed to infectious bovine rhinotracheitis, when the real sequence of events begins with colostrum quality, followed by fluctuating ventilation, then a weather front that pushes calves over the edge.
A feedlot dip in performance linked solely to a ration change, when heat stress, water access, bunk competition and handling stress created a cascade of interacting pressures.

Each diagnosis contains a piece of truth, but each is incomplete when treated in isolation.

Systems Thinking: Looking Between the Parts

Systems thinking is the discipline of understanding how elements interact to produce outcomes. It challenges us to stop asking what caused this and start asking how these factors combined to create this situation.

Dr. Brian Vander Ley of the University of Nebraska-Lincoln recently spoke on the topic.

“Systems thinking is actually a derivative of a field called ‘systems dynamics,’ which is a highly mathematical modeling field that’s used to predict the behavior of systems based on components in the system and relationships,” Vander Ley explains. However, systems thinking takes out the math component. “It’s a set of tools, processes and principles that enable us to focus on the relationship between parts of the system and not just some of the parts themselves.”

A system isn’t just a list of components. It is:

The feedback loops between nutrition and immunity
The way ventilation interacts with pathogen load
How handler behavior influences stress physiology
How management timing affects microbial dynamics
How one week’s decisions become the next month’s disease patterns

The iceberg analogy fits here too: What we see in the cow is only a small fraction of what’s really happening. The larger drivers of disease sit below the surface and remain invisible unless we deliberately go looking for them.

The heart of systems thinking is recognizing that diseases are rarely linear. They are networked. They emerge not from one factor but from several interacting simultaneously, sometimes amplifying, sometimes buffering each other.

In other words, the elephant is not just trunk + tusk + leg + ear. The elephant is the relationships that connect those parts into a living organism.

The Veterinarian as a Systems Navigator

Veterinarians already intuitively use systems thinking. You’re constantly piecing together physiology, environment and behavior. The challenge is doing it intentionally rather than incidentally.

This means asking broader questions:

Where did the system fail and why?
What feedback loops are reinforcing the problem?
Which variables are upstream versus downstream?
What invisible pressures are shaping what I can see?
What happens if one part of the system changes?

When we ask these questions, we stop thinking like the blind men — competing diagnoses based on isolated observations — and start thinking like systems analysts, integrating multiple perspectives into a coherent picture.

This is also dependent on communication within the animal care team.

“Communicating about it is really important, because we are really sure about our own experiences. When I go out and collect data with my own hands and my own eyes, I’m very confident in that data, and when I see information that’s very different, I tend to disregard that information,” Vander Ley says. “We want to engage in a kind of communication that allows us to appreciate that we’ve got different pieces of the elephant in hand.”

Having an open dialogue between owners, producers, veterinarians and academics allows for a broadened perspective for understanding what the problem is.

Case Example: Reframing a ‘Simple’ Mastitis Problem

Take a herd with climbing somatic cell count and increased clinical mastitis cases. A parts-focused approach might look at:

Teat-end condition
Milking protocols
Bedding
Culture results

A systems approach goes further:

How has cow flow changed through the parlor?
Are fresh cows being mixed too early?
Has ration moisture affected rumen health and lying time?
Are staff changes altering consistency in milking prep?
Has heat stress reduced rumination and immune resilience?
Are equipment cleaning routines changing due to workload?

Suddenly, the rising cell counts are no longer an udder health issue but a system problem — a signal, not a cause.

Stepping Back to See the Elephant

The parable of the blind men isn’t merely about limited perspectives; it’s about the illusion of certainty that comes from seeing only one piece of a larger, interconnected whole.

Veterinarians do some of their best work up close: palpating, listening to internal sounds, evaluating subtle signs. But the greatest diagnostic breakthroughs often come when we deliberately widen our view and consider not just the parts but the interplay between them.

Systems thinking doesn’t replace traditional diagnostic skills, it evaluates them. It turns isolated observations into meaningful patterns. It turns symptoms into stories. It turns disease into a map we can navigate instead of a puzzle we must solve.

In the end, seeing the ‘elephant’ means seeing not just the cow or the herd but the interconnected ecosystem that shapes every outcome.

Equine Herpesvirus Cases Continue to Climb After Outbreak in Texas

Fri, 21 Nov 2025 21:05:33 GMT

A wave of concern is sweeping across the U.S. equine industry as a cluster of confirmed cases of Equine Herpesvirus-1 (EHV-1) has been linked to the Women’s Professional Rodeo Association World Finals and Elite Barrel Race event held November 5-9 in Waco, Texas. Since this event, EHV-1 infection has led to 15 confirmed cases of equine herpesvirus myeloencephalopathy (EHM) with seven cases in Texas, three each in Louisiana and Oklahoma, and one each in Colorado and New Mexico.

This number has doubled in the past 36 hours, according to case reports by the Equine Disease Communication Center .

EHV-1 is a highly contagious virus in horses that can cause respiratory and reproductive issues and neurological disease. It spreads among horses through direct contact with respiratory secretions, inhalation of aerosolized respiratory droplets (distances less than 30'), or contact with contaminated people or equipment.

With virus spread possible, it’s important to be vigilant with quarantining and reducing exposure. This includes preventing the movement of exposed horses, and avoiding sharing any grooming equipment, water and feed sources, or any other tools between infected and healthy horses. Also take care to change your clothes and thoroughly wash your hands and arms after working with infected horses. It is important to note that this virus can survive in the environment for several weeks.

Texas agriculture commissioner Sid Miller issued an alert earlier this week:

“The virus can spread fast, it can be deadly, and the earliest signs are often so subtle they’re easy to miss. That’s why monitoring your horses right now is critical. The quicker we identify a potential case, the better chance we have to protect not only our animals, but the entire Texas equine community.”

Monitoring for and Limiting EHV-1 Infection

The clinical signs of EHM include:

Fever
Incoordination or limb weakness (especially hind limbs)
Urine dribbling
Decreased tail or anal tone
Inability to stand

Dr. Dusty Nagy, chief medical officer of the Texas A&M Large Animal Hospital, advises horse owners, trainers and practitioners to closely monitor their animals and check their temperatures at least twice daily. Fever is often the first indicator of EHM, but can it fluctuate through the day.

Nagy believes the numbers will only climb as the incubation period for the initial exposure increases.

“I do think that is probably an understatement for where we are right now as there’s a lot of testing pending,” Nagy says. “There are definitely horses out there that have been exposed, that are shedding, that appear healthy.”

To prevent further spread of this highly infectious virus, Nagy urges all horse owners to quarantine their horses.

“I recognize that there’s a lot of high end equine athletes that are involved in this, and this is a big time of the year for them. That’s a hard recommendation to take, but I do think the easiest way to stop or slow it down is to stop animal movement,” Nagy says.

Vesicular Stomatitis Outbreak in Arizona

Fri, 14 Nov 2025 16:34:09 GMT

USDA’s Animal and Plant Health Inspection Service has released a situation report on vesicular stomatitis virus (VSV) after the virus was identified on two Arizona farms this month.

While both reported cases were in horses, VSV also affects cattle, swine and other ruminants. The farms on which the virus was identified both also house cattle, though none have been found to be clinically affected.

In response to this outbreak, the Canadian Food Inspection Agency (CFIA) has announced temporary import restrictions on horses, ruminants and swine from the U.S. until further notice. The import of horses, swine and ruminants from VSV-affected states for all purposes is prohibited. Animals from other states that have been in a VSV-affected state at any point in the three weeks prior to import will be denied entry to Canada. Special accommodations have been made in collaboration with USDA regarding animal import for major Canadian livestock competitions and exhibitions.

What is Vesicular Stomatitis?

Vesicular stomatitis (VS) is a viral disease primarily spread by biting midges and flies, but can also be spread via animal-to-animal contact or exposure to saliva or fluid from ruptured vesicles. It is also important to protect yourself if working with infected animals as it is transmissible to humans causing an acute influenza-like illness.

VS is named for its characteristic vesicular lesions that form around the mouth, nose, udders and hooves. Along with these lesions, clinical signs of VS include:

excessive salivation (often accompanied by raised blisters on the lips, gums and tongue)
fever
feed withdrawal leading to weight loss

In cattle and horses, lesions around the hooves can lead to lameness, while teat lesions in dairy cattle can lead to mastitis and a severe drop in milk production. Affected swine usually first show signs of lameness caused by foot lesions.

Controlling Vesicular Stomatitis

While VS does not usually cause the death of an animal, it can lead to economic losses due to prevented animal movement and impacts on international trace. Farms with VSV positive animals must quarantine for 14 days after lesions appear on the last case at the location.

The last VS outbreak occurred from May 2023 through January 2024 affecting 319 locations across California, Nevada and Texas. VSV circulates annually between livestock and insect vectors in southern Mexico, only entering the U.S. when environmental factors support the northern movement of vectors.

If you suspect an animal might be infected with VSV, you should immediately contact local state and federal animal health authorities.

The Asian Longhorn Tick Moves West to Kansas

Fri, 10 Oct 2025 15:34:59 GMT

The Asian longhorn tick (ALHT) has now been identified in Kansas . The tick was submitted to the Kansas Department of Health and Environment for identification after being found on a dog in Franklin County last week. This represents the western most occurrence of the tick; it was last found in Iowa in June, 2025.

ALHT was first identified in the U.S. in 2017 in New Jersey. Since then it has gradually spread westward and has been documented in 21 states according to USDA .

These ticks are a threat to both human and animal health. ALTH are known to carry Theileria, a protozoan parasite that infects red and white blood cells. Theileria can lead to anemia and even death. Typically, cattle affected by Theileriosis will show signs of lethargy and difficulty breathing.

Because the female tick can reproduce without a male and lay up to 2,000 eggs at a time, a single tick can lead to a major infestation on a single animal leading to reduced growth and production, and, in the most severe cases, death from blood loss.

Cattle producers should be on high alert for external parasites on their animals. While their activity might decrease in the winter months, the ALTH can survive for up to six months off an animal and is tolerant of the cold.

For more information on the ALHT, check out:

Beef Producers Be Aware: Dangerous Asian Longhorned Tick Continues Migrating West

Theileria and the Asian Longhorned Tick: What Beef Producers Need to Know

Harness the Full Potential of Your BRD Vaccine with the Right Adjuvant

Mon, 29 Sep 2025 10:38:32 GMT

Bovine respiratory disease (BRD) is one of the greatest threats to young calves, and gaining protection through vaccines isn’t always straightforward. Maternal antibodies, passed through colostrum, can block some vaccines from boosting immunity. The key to overcoming that hurdle? Choosing a vaccine with the right adjuvant.

Maternal Antibodies Can Interfere with Vaccines

“Years ago, vaccine response was so variable in young calves,” says Curt Vlietstra, DVM, Boehringer Ingelheim. “At the time, we didn’t know if their immune system simply wasn’t ready, or if there was a problem with the vaccines. With the research we have now, we understand that the majority of interference comes from maternal antibodies that are still present in the calf at the time of vaccination.”

Passed down from the cow via colostrum, maternal antibodies are not only a calf’s first line of defense against disease, but they also have the tendency to neutralize vaccines.

Those maternal antibodies naturally wane when the calf is between 2 and 6 months of age. As this maternal immunity dwindles, vaccination becomes critical in boosting and building calf immunity. The largest challenge in bridging these two forms of immunity is timing. Chris Chase, DVM, Professor, Department of Veterinary and Biomedical Sciences, South Dakota State University, says finding a vaccine with the right adjuvant can eliminate this guessing game.

Adjuvants Are Critical to Capturing Immunity in Young Calves

Adjuvants — although often overlooked — can determine whether a calf successfully develops a robust, lasting immune response, or remains vulnerable to BRD pressure. They work by drawing immune cells to the injection site, and helping the calf’s body recognize and remember the vaccine. Some adjuvants also slow the release of the vaccine, giving the immune system more time to respond.

“With the types of adjuvants we have now, we can get strong, long-lasting immune responses, even in calves with maternal antibodies,” Chase shares. “Although, just because a vaccine label says ‘adjuvanted’ doesn’t mean it offers the protection we need. It’s important that we ask what kind of adjuvant it is and what it’s proven to do.”

Over the last few decades, peer-reviewed studies and fieldwork have shown that Pyramid ^® vaccines can succeed, even in the face of maternal immunity, thanks to its unique adjuvant, Metasim^®. Specifically designed to address the challenges of early calfhood vaccination, the dual-phase technology of the Metasim adjuvant can stimulate a balanced, robust immune response in calves as young as 30 days of age.

(Boehringer Ingelheim)

“Historically, it was accepted as fact that maternal antibodies would block the injectable vaccine,” Vlietstra says. “Now we know Metasim works alongside the preexisting antibodies, not against them.”

Systemic Immunity Builds Long-Lasting Protection

Another key factor in vaccine selection is delivery method. For a time, intranasal vaccines were thought to be the only effective option to protect young calves against BRD. While intranasal vaccines can offer local immunity for calves at risk of BRD exposure soon after birth, some may miss the opportunity to stimulate robust, systemic immunity.

While local immunity helps block infection right where it starts (which is usually in the respiratory tract with BRD), systemic immunity is what builds broad, long-lasting protection, by training the calf’s entire immune system to respond.

When calves encounter BRD pathogens weeks or even months after vaccination, a strong systemic immune response helps them recognize and fight off infection more effectively, reducing severity of disease and its long-term impact on health and performance.

“In some ways, we’ve become very reliant on intranasals,” Vlietstra notes . “I’ve seen protocols that say, ‘This calf may not respond to an injectable, so let’s give another intranasal.’ That choice ends up potentially delaying systemic protection.”

Injectable vaccines with the right adjuvant have been proven to stimulate both local immunity in the respiratory tract, and systemic immunity that circulates in the bloodstream.

Even the Best Vaccine Needs Correct Timing and Care

“There are plenty of producers and veterinarians who have firsthand experience of vaccines not working,” Vlietstra says. “If we’re not seeing results, it’s time to evaluate how we’re using the product and when.”

It’s common to schedule vaccination alongside other times calves are being worked, like weaning or transportation. While this may save labor and time up front, vaccinating calves during other stressful events can limit immune response.

“If cattle have had a long truck ride, ideally, we’d let them unload and rest for 24 to 48 hours before we vaccinate,” Chase explains. “I know not all operations have the resources to do this due to labor constraints, but water and rest time after a stressful event will set cattle up for a better immune response.”

To get the most of any vaccination program, good animal handling, husbandry and biosecurity protocols play a role in preventing and controlling BRD. By staying on top of health management and using products according to label, vaccines are more likely to capture desired results.

“The world’s best vaccine is not going to overcome overwhelming challenges,” Chase stresses.

The needs of every herd are different. Working closely with a veterinarian is key to finding success tailored to your cattle and operation.

Texas A&M Researchers Study Diet’s Impact On Salmonella Prevalence In Cattle

Fri, 22 Aug 2025 15:28:13 GMT

Salmonella is one of the leading causes of foodborne illnesses in the U.S., according to the Centers for Disease Control and Prevention, and can spread to people from a variety of foods, including beef. Understanding how and why cattle become infected with Salmonella is an important part of fighting this major public health concern.

Researchers at the Texas A&M College of Veterinary Medicine and Biomedical Sciences (VMBS) are addressing this problem from a new angle by studying how diet and feeding schedule impact Salmonella infections in cattle.

Their recent study , published in the American Society for Microbiology’s Microbiology Spectrum journal, found that high-starch diets can potentially lower Salmonella prevalence in cattle, especially within the lymph nodes — organs that are often embedded in fat trims included in ground beef products.

“Lymph nodes may be present in fat trimmings that are used to balance lean-to-fat ratios in ground beef products,” says Yesica Botero, a fourth-year biomedical sciences doctorate student. “This is a food safety concern because Salmonella can hide inside lymph nodes, where surface cleaning or treatments do not reach. As a result, it can still be present in ground beef.”

Feedyard cattle are typically fed a high-energy, grain-based diet designed to promote rapid growth and efficient weight gain.

Understanding the role that a high-starch diet potentially plays in reducing Salmonella prevalence could have major impacts on the beef cattle industry, providing ranchers with new options for controlling the spread of bacteria within their herds.

Taking A New Approach

The Texas A&M project was designed to study feedlot cattle that Dr. Kendall Samuelson, from West Texas A&M University, was examining in a separate project to see whether high-starch diets and feeding schedules impact liver abscess formation.

“We aimed to understand the factors that contribute to the presence and distribution of salmonella in feedlot cattle,” said Dr. Gizem Levent , a VMBS assistant professor in the Department of Veterinary Integrative Biosciences . “There aren’t many studies focusing on understanding how diet and management changes impact Salmonella.”

Botero and Levent took samples of feces, hides, lymph nodes and soil from Samuelson’s cattle pens over a period of more than seven months. They found that while there was little difference in Salmonella populations between cattle with scheduled versus erratic feedings, the level of starch in the diet made a notable impact.

“We saw a reduction in Salmonella, especially in the lymph nodes, when cattle were fed a high-starch diet,” Botero says. “High-starch diets typically cause a lower pH in the rumen, which may be what reduces Salmonella prevalence in the gastrointestinal tract and, subsequently, in lymph nodes.

“Findings from Dr. Samuelson’s original study suggested that high-starch diets may also correlate with a higher incidence of liver abscesses,” she says. “This is something we would like to explore further in upcoming studies by testing different starch concentrations in the diet to find one that does not harm cattle health — such as by increasing the risk of liver abscesses — but still helps lower Salmonella levels.”

Continuing The Investigation

In addition to studying how different levels of starch impact liver abscesses and Salmonella, Levent and Botero are planning to dive even deeper into the data to study the specific serotypes, or genetic profiles of Salmonella, observed in their samples.

“We want to do a follow-up study with more in-depth analysis of the dynamics of the Salmonella population,” Botero says. “By looking at the genetic profiles, we can better understand which serotypes are present, how they might respond to antibiotics, and whether they carry genes that make them more likely to survive or spread in the environment.”

Fortunately, what they have seen so far from the feedlot samples does not indicate a high presence of Salmonella or serotypes resistant to antibiotics.

“The overall Salmonella population found was not resistant to antibiotics of public health concern, which is good news for public health,” Levent said. “But we will definitely keep screening for resistance so that we can better understand what makes resistant populations exist in the environment.”

Bull Tests Positive for Brucellosis: Herd Quarantined and Investigation Continues

Thu, 21 Aug 2025 16:08:05 GMT

On Friday, August 15, the Montana Department of Livestock (MDOL) received confirmation that an animal from a Beaverhead County herd within Montana’s Designated Surveillance Area (DSA) tested positive for brucellosis.

According to a press release , the herd has been placed under quarantine pending the completion of an epidemiological investigation.

The positive bull was identified as a brucellosis suspect during required testing at a livestock market in late July. The animal was euthanized and taken for necropsy at the Montana Veterinary Diagnostic Laboratory where tissues were collected and sent to the USDA National Veterinary Services Laboratory (NVSL) in Ames, Iowa, for confirmatory testing. NVSL was able to grow the Brucella abortus organism from one of the lymph nodes collected from the animal.

The disease investigation will include testing and tracing of animal contacts and movements to ensure the disease is not present in other livestock herds. MDOL will work with the affected operation to minimize the impact of this diagnosis by conducting a tailored and focused investigation.

Montana’s Designated Surveillance Area (DSA)

(Montana Department of Livestock)

Montana’s DSA exists due to the risk of disease spillover from infected wildlife in the Greater Yellowstone Area (GYA). Program testing requirements help ensure cases of brucellosis in livestock are detected before animals leave the DSA. Successful early detection provides confidence to Montana’s trading partners that any Montana cattle they may receive are brucellosis free. Brucellosis causes reproductive issues in livestock including abortions, still births and neonatal mortalities.

“While detections of brucellosis are a hardship on operations, this detection is still a reflection of the success of our state brucellosis program,” says Dr. Brenee Peterson, MDOL veterinarian. “Through the work of DSA producers and local veterinarians, we continue to detect the disease early and prevent the export of a brucellosis-infected animal to one of our trading partners.”

Previous Brucellosis Detection

This herd is the 14^th brucellosis-affected herd confirmed in Montana since the implementation of the DSA in 2010. The most recent detection was within the DSA in Madison County in April 2023. While the source of infection for this latest infected bull has not yet been determined, DNA genotyping and epidemiological investigations have concluded the previous 13 infections came from wild elk. Prior investigations have also confirmed brucellosis has not spread to neighboring herds through fence-line contact.

What is Brucellosis?

According to USDA’s Animal and Plant Health Inspection Service (AHIS) brucellosis (also known as contagious abortion or Bang’s disease) is a costly disease of livestock and wildlife. It is caused by a group of bacteria in the genus Brucella. The disease has significant consequences for animal health, public health and international trade.

Brucellosis occurs mainly in cattle, bison and swine, but can affect other animals (cervids, goats, sheep and horses) as well as people.

In cattle and bison, the bacteria of concern is Brucella abortus. It has been present in the U.S. since the 1930s. A longstanding national eradication program mostly eliminated the disease in U.S. cattle. Today, only occasional spillover cases occur in cattle and other livestock near the GYA. Wild bison and elk in the GYA are the last remaining reservoir of this disease in the U.S.

According to the APHIS website , when signs do appear, they’re most obvious in pregnant animals. Here’s what to look for:

Abortion (usually at five to seven months of pregnancy)
Birth of weak, unhealthy calves
Decreased milk production
Weight loss
Poor conception rates or infertility
Retained afterbirths with resulting uterine infections
Enlarged, arthritic joints (occasionally)

“Appearance alone isn’t an effective way to detect brucellosis,” according to the website. “Infected animals may appear healthy, even during pregnancy. However, they can still harbor and spread infectious bacteria and serve as dangerous sources of infection.”

Producers or owners who suspect an animal disease should contact their veterinarian to evaluate the animal or herd.

Emergency Use of Animal Drugs Approved to Combat New World Screwworm

Tue, 19 Aug 2025 16:08:11 GMT

The U.S. Department of Health and Human Services (HHS) issued a declaration on Aug. 19 allowing the U.S. Food and Drug Administration (FDA) to issue Emergency Use Authorizations (EUAs) for animal drugs to treat or prevent infestations caused by the New World screwworm (NWS).

This declaration applies only to drugs for animals. NWS infests warm-blooded animals, including livestock, pets, wildlife, and, in rare cases, humans, causing severe tissue damage and sometimes death. The risk to human health in the U.S. remains very low, but the potential future threat to animal populations and the food supply chain requires proactive action.

Although eradicated from North America and Central America decades ago, NWS has progressed north since 2022 and is now approaching the U.S. border with Mexico. This parasite poses an emerging threat to livestock and food security, with potential impacts on both national security and animal health.

“Today we are taking decisive action to safeguard the nation’s food supply from this emerging threat,” says HHS Secretary Robert F. Kennedy, Jr. “This authorization equips FDA to act quickly, limit the spread of New World Screwworm, and protect America’s livestock.”

Currently, there are no FDA-approved drugs for NWS in the U.S. The FDA through an EUA can authorize the flexible, faster use of certain animal drug products that may be approved for other purposes, or available in other countries, but not formally approved for NWS in the U.S. This ensures veterinarians, farmers, and animal health officials have timely access to the tools they need to protect pets, livestock and the nation’s food supply.

“Thank you to my friends and partners Secretary Kennedy and Commissioner Makary who are answering the call and supporting our aggressive plan to push back and ultimately defeat this devastating pest. This emergency use authorization is another tool we can use in the fight against New World Screwworm,” says Secretary of Agriculture Brooke L. Rollins. “Our cattle ranchers and livestock producers are relying on the Trump Administration to defend their livelihoods. Stopping this pest is a national security priority and we are linking arms across President Trump’s cabinet to defend our borders and push back this threat.”

FDA Commissioner Marty Makary, M.D., M.P.H., adds, “Our priority is to safeguard both animal health and the nation’s food supply. FDA is acting swiftly and responsibly to help ensure we have the necessary tools to prevent and control New World Screwworm, minimizing risks to agriculture and public health.”

FDA will provide future guidance to veterinarians and stakeholders on the appropriate use of any products authorized for emergency use and update the New World Screwworm: Information for Veterinarians page.

Theileria and the Asian Longhorned Tick: What Beef Producers Need to Know

Wed, 06 Aug 2025 15:05:50 GMT

The Asian longhorned tick (ALHT) poses a serious threat to cattle health. ALHTs carry Theileria, which is a protozoan parasite that infects red and white blood cells. It can lead to anemia and, in some cases, death.

In the U.S., ALHT was first detected in New Jersey in 2017. Since then, it has spread to more than 20 states. With the recent discovery of ALHT in southeast Iowa , the Iowa Cattlemen’s Association hosted a webinar lead by Cassandra Olds, Kansas State University Extension entomologist, who explained the tick and pathogen background, its potential impacts, best practices for prevention, as well as caring and treatment strategies.

“This was always a when, not an if,” Olds explains. “You did absolutely nothing wrong. If you have the tick or the pathogen, this was an inevitable thing.”

What We Know about ALHT and Theileria

Biologically, the ALHT is a three-host tick, meaning each life stage — larva, nymph and adult — feeds on a different host. Olds says unlike other tick species, it can reproduce asexually, with all adult ticks being females capable of laying eggs without mating. This characteristic allows for rapid population growth, as a single tick can potentially establish an entire population.

Once an animal is infected with Theileria, it becomes a chronic carrier for life, with the potential to relapse during high-stress periods. The pathogen replicates in red blood cells, causing anemia and a range of symptoms including loss of appetite, weight loss, fever and respiratory issues.

Olds says while the first year of exposure can be challenging, long-term production impacts are typically minimal. The key is to approach the situation with knowledge, preparedness and a calm, strategic mindset.

She stresses that just because a cow herd does not have the symptoms doesn’t mean it doesn’t have Theileria. It just means that if an animal was infected, it didn’t develop the disease.

She reports mortality rates due to Theileria range from 5% to 20%. With the highest mortality when pathogen is first introduced — the outbreak. An animal can have a relapse of disease, often during high stress or immune compromising events.

She explains the high-risk animals are young (under 6 months), pregnant animals, stressed animals and any naïve animal moving into an area with previous outbreaks.

Best Practices for Prevention

Olds notes the pathogen can spread through tick bites and through shared veterinary needles. She says her team is currently researching the role of biting flies in transmission.

She stresses the importance of maintaining animal health and reducing stress to prevent disease outbreaks.

“Keep animals happy and healthy. Stress does weird things to immune responses,” she adds.

According to Olds these strategies can help control AHLT:

Burning pastures
Keeping grass short
Careful use of insecticides
Pasture rotation
Ear tags and pour-ons

(Data: Oklahoma State University; Tick Photo: J.A. Cammack)

Real-World Experience

Veterinarians John Currin and Austin Williams share their firsthand experiences with ALHT and Theileria.

Currin serves as associate professor and production management medicine with the VA-MD College of Veterinary Medicine at Virginia Tech. He says in his area more than 90% of the herds are infected and many don’t know they’re infected.

“The tick epidemiology is — I’ll use a scientific term — weird,” he says.

He explains as the disease became endemic in Virginia, its clinical presentation changed. While it initially affected adult pregnant cows, it now more commonly impacts 2-month-old calves in spring calving herds.

“There is no in utero spread of this organism, so every calf starts naïve,” Currin says.

Approximately 80% of calves in infected herds become positive by 3 months of age, though most do not show severe clinical signs.

He adds contrary to initial concerns the Theileria appears to have minimal impact on cattle in a feedlot. Currin says research found no significant differences in weight gain between negative and positive cattle.

He stresses the primary concern is for cow-calf operations bringing naive animals into infected areas.

Currin shares these key points about Theileria:

99% of herds will experience minimal problems
Most infected animals show no significant clinical signs
The disease primarily causes anemia
There’s no direct treatment available
Positive tests are now almost meaningless in endemic areas

Williams serves producers in northwest Arkansas and southwest Missouri.

“I think it’s been here longer than we recognize and it’s more widespread than what we realize it too,” he says. “I would say some states have it that don’t know they have it.”

In Williams’ area he has seen the tick infestation become widespread. The key challenges he’s witnessed is the difficulty of managing the tick population and the potential for secondary health issues in infected cattle.

He recommends individual herd management strategies, including regular checks, treatment plans and potentially moving infected herds to different pastures.

Treatment Strategies

There are currently no labeled treatments for the disease or a definitive cure. Typically, treatment focuses on secondary issues and providing basic care.

Avoid mass injecting ivermectin, as it can cause resistance and harm beneficial insects like dung beetles.

“Please don’t just mass inject everybody with ivermectin because you’re worried about the Asian longhorned tick,” Olds says.

Vaccine Developed

Medgene has developed a tick vaccine that is designed to work on multiple tick species, including ALHT. Veterinarians can purchase directly from Medgene. The vaccine requires two initial doses, followed by yearly booster shots.

Williams says he’s had clients use the vaccine this year, and he’s hopeful about the vaccine’s potential and is waiting for more research from the University of Arkansas to provide concrete data on its effectiveness.

Gary Bosch, Medgene executive vice president, says animals should be vaccinated before they encounter ticks.

“In the Southern U.S. where ticks are a year-round problem, early vaccination is especially crucial because the Asian longhorned tick can overwhelm an animal very quickly,” he says.

Industry Impacts

Olds says the goal is to achieve “endemic stability” — when most animals are exposed early and develop lifelong immunity with minimal disease symptoms.

She emphasizes the need to remove the stigma associated with the tick or pathogen presence, noting that infection is an inevitable part of agricultural reality. Producers should focus on proactive testing, management and community support.

To prepare for and to deal with Theileria, Olds recommends producers:

Establish a good relationship with a veterinarian
Conduct regular herd testing
Maintain low-stress environments
Implement careful tick control measures
Share information and support each other as a community

Her final advice is to be vigilant but not panicked.

“Producers should view the Asian longhorned tick as a manageable challenge rather than a catastrophic threat,” she summarizes. “By working together, maintaining animal health and implementing smart management strategies, the agricultural community can effectively navigate this emerging issue.”

Your Next Read: Beef Producers Be Aware: Dangerous Asian Longhorned Tick Continues Migrating West

Risk Factors Associated with BRD in Preweaned Calves

Fri, 01 Aug 2025 13:55:32 GMT

A well-managed Midwest cow-calf ranch has a problem with respiratory disease in its preweaned calves. They retain ownership, artificially inseminate and manage everything well according to Kansas State Veterinarian Brad White.

During a recent “ Bovine Science with BCI ” podcast, Kansas State University veterinarians Brad White and Bob Larson explore potential causes for bovine respiratory disease (BRD) in preweaned calves and how to mitigate the problem. White says discussing how to deal with preweaning BRD with producers can be frustrating because clear answers are not always possible.

Larson explains typical BRD preweaning symptoms for a spring calving herd will show up midsummer when the calves are about 4 months of age or a little older and still nursing on pasture.

“We could see 15% to 20% of the calves display symptoms,” Larson explains. “What we’re looking for is kind of typical, depressed, their heads down, maybe rapid breathing, those types of things. They’re not really being aggressive with their suckling or eating or anything.”

Larson reminds producers this fits the same description of respiratory disease in older calves. He says, likewise, some death loss can occur.

“Probably the most common what I see is up to 20% of the calves are affected, and from among those that we treat, you get just a few deaths,” he says.

Research Findings

Larson explains a recent K-State research project regarding BRD. Research surveys of more than 400 herds revealed several key insights. Several potential risk factors were identified that could contribute to preweaning respiratory disease:

Artificial Insemination (AI) and Synchronization. Gathering cattle for AI can increase disease transmission and changing pasture dynamics and increasing close contact among calves.
Management Practices. If cattle are managed using intensive grazing strategies or creep feeding these practices that alter normal grazing patterns and increase calf interaction and thus disease transmission.
External Exposure. Grafting calves into a herd, grazing stocker cattle in the same pasture or any introduction of outside animals can be a potential risk factor.
Immunological Factors. Declining maternal antibody protection at 3 to 5 months of age. Front-loaded calving seasons creating a cohort of calves vulnerable at the same time.

Larson stresses this is speculation because many herds do those types of practices and do not have a summer pneumonia problem.

“So, it’s not a smoking gun that if you do these practices, you’ll run into summer pneumonia,” he summarizes. “It’s just that we saw a little bit higher risk in those herds that did some of these, again, kind of changing the normal grazing distribution and pattern that calves interacted.”

Larson and White share several prevention and management strategies:

Maintain strict biosecurity
Isolate grafted or new calves
Avoid commingling different cattle groups
Ensure good nutrition and sanitation
Consider vaccination protocols carefully

During the podcast , the researchers highlight the complexity of preweaning BRD, noting that no single factor guarantees prevention. Each herd requires a tailored approach and working closely with a veterinarian to understand specific risk factors.

The primary takeaway is that while preweaning BRD is frustrating and not entirely predictable, producers can mitigate risks through careful management, biosecurity and proactive health strategies. Good, foundational practices such as maintaining cow health, providing a sanitary environment and monitoring the herd remain the most critical components of prevention.

Producers experiencing recurring issues should reassess their management practices, vaccination protocols and herd dynamics to reduce the likelihood of preweaning respiratory disease outbreaks.

Researchers Offer Advice From New World Screwworm Experience

Fri, 18 Jul 2025 11:02:40 GMT

During the 2016 New World screwworm (NWS) outbreak in Florida among the state’s Key deer, which are a federally endangered wildlife species, two Texas A&M researchers were on the frontlines of the eradication efforts and offer lessons learned.

Roel Lopez, Ph.D., director of the Texas A&M Natural Resources Institute and head of the Texas A&M Department of Rangeland, Wildlife and Fisheries Management, and Phillip Kaufman, Ph.D., head of the Department of Entomology, share advice to help shape science-based outreach, surveillance and containment strategies in Texas.

Reflecting on screwworm infestation threat to endangered Florida deer

In 2016, a case of confirmed infection of NWS in Key deer marked the first U.S. outbreak of the flesh-eating pest in more than 30 years.

Lopez says this caught many wildlife biologists off guard.

“Frankly, many of us who had never dealt with New World screwworm were unsure of the survival of Florida’s Key deer,” he says.

The Key deer is the smallest subspecies of white-tailed deer and only inhabits the Florida Keys, a string of islands off the southern tip of the state.

Lopez and others in the Texas A&M Natural Resources Institute were called upon by the U.S. Fish and Wildlife Service to monitor Florida Key deer populations. They were asked to assess the impact of the infestation and aid in establishing recovery strategies, his team’s fieldwork became part of a large-scale, coordinated response effort.

From Florida entomologist to Texas advisor

During that time Kaufman served as University of Florida’s Institute of Food and Agricultural Sciences Extension scientist and associate professor and was a key source of information on the NWS fly and its biology.

“County Extension agents are who local populations go to for answers,” Kaufman says. “It was up to us to provide them with the most up-to-date materials, so they knew what was occurring and what to be on the lookout for.”

Multi-agency response leads to fly containment and eradication

Containment and eradication efforts in Florida were a multi-agency effort, according to a Texas Agri-Life release. Strategies included the release of sterile male flies, mandatory checkpoints, treatment of impacted and vulnerable animals with deworming agents, and ongoing monitoring. Within months, the outbreak was contained and the NWS ultimately eradicated in Florida.

“It took a tremendous amount of coordination between various agencies and groups to reach that point,” Lopez says. “The biggest lesson I learned was the importance of rapid, interagency coordination. No one agency can do it themselves — it requires a cohesive effort.”

The infestation did not spread to Florida’s mainland, infecting additional wildlife or impacting the state’s livestock industry. However, it caused approximately 15% of the Key deer population to be killed.

Experts advocate vigilance, reporting suspicious cases

While NWS has not yet crossed into Texas, Lopez and Kaufman urge vigilance from landowners, veterinarians and wildlife managers, asking them to report any suspicious cases that could indicate its presence.

“If you see something, say something,” Lopez says. “It is better to have been mistaken than to inadvertently allow this pest to gain a foothold in the state.”

The impacts to wildlife and livestock could be devastating if NWS reaches the southern border and into the U.S. White-tailed deer hunting alone contributes billions of dollars to the Texas economy annually.

“The biggest challenge with wildlife is monitoring and early detection,” Lopez says. “With this in mind, investigation of suspicious mortalities or the use of game cameras can serve as an invaluable tool for landowners to monitor wildlife health and document any signs of infection.”

Kaufman says confined wildlife operations should develop herd management plans similar to those used by livestock producers.

“If you are running a wildlife facility, you need to have a biosafety plan,” he says. “Develop a surveillance program for your ranch and have a list of veterinarians and resources on hand.”

In some cases, Kaufman says these operations may consider equipping their most high-value animals with tracking devices to monitor their movements.

“The outbreak in Florida occurred without any prior warning indicators,” Kaufman says. “Because we are currently aware of the New World screwworm’s northern movement in Mexico, Texas is in a better position to proactively plan and execute an effective response.”

How to report suspected cases

Promptly report any signs or suspensions of NWS to the proper authorities:
Domestic animals: Contact your local veterinarian.
Wildlife: Contact your Texas Parks and Wildlife Department county wildlife biologist.
State and federal reporting:
Texas Animal Health Commission: 800-550-8242
U.S. Department of Agriculture Veterinary Services: 512-383-2400

Your Next Read: The Smell You’ll Never Forget: A Calf Infested with New World Screwworm

Kansas Beef Producers Beware: A Case of Theileria Found

Thu, 17 Jul 2025 18:51:08 GMT

Theileria orientalis ikeda, a protozoan parasite that infects red and white blood cells and can lead to anemia and, in some cases, death, has been found in Kansas.

The primary insect vector is the Asian longhorned tick (ALT) . According to the Kansas Veterinary Diagnostic Laboratory (KSVDL) ALT has not been found in Kansas but has been found in Missouri, Arkansas and in Oklahoma most recently in the county adjacent to Labette County, Kan.

The disease can be spread through multiuse needles and insect vectors.

KSVDL reports the infected calves in the case were purchased on the East coast and imported into Kansas for feeding.

If you are witnessing any of these clinical signs in cattle of all ages — anorexia, lethargy, dyspnea, icterus or death — please consider this new pathogen.

KSVDL also stresses producers need to be wary of importing cattle without testing for this disease. KSVDL has a polymerase chain reaction (PCR) (MDL7130) that identifies both Anaplasma and Theileria. As with all PCR’s, whole blood (purple top tube) is the appropriate antemortem sample. Fresh spleen is the appropriate postmortem sample.

KSDVL has a map of where the disease has been confirmed by KSDVL testing.
For more details on the disease, you can view a webinar produced by KSDVL.

7 Tips for Preventing Pinkeye

Wed, 16 Jul 2025 16:36:40 GMT

Pinkeye is a contagious and widespread cattle bacterial eye disease found worldwide. Although non-fatal, it can cause substantial losses to the cattle industry through decreased weight gain, lowered milk production and treatment costs.

Like many diseases, management is often the most effective and economical method of disease control. When environmental conditions, animal nutrition and herd immunity are properly managed, animal health increases and disease frequency decreases.

Treatment works, but treating one cow – let alone several – takes time. According to an Oklahoma State University fact sheet , there are seven strategies producers should implement to prevent the disease.

1. Fly control. Controlling face flies also goes a long way in preventing an outbreak. Remember, flies spread the Moraxella bovis bacteria from animal to animal. Insecticide fly tags, sprays, charged backrubbers and dust bags are products that can provide chemical control. Use of feed through growth regulators may help reduce the fly population. Manure management can be beneficial in controlling stable and house flies in confinement operations.

2. Grass, weed and brush control. According to Richard Randle, University of Nebraska Extension beef cattle veterinarian, a good prevention program should incorporate procedures to reduce initial eye irritation. This strategy includes grazing management, mowing, brush mowing and spraying to minimize pollen and mechanical irritation.

3. Hay and/or feed bunk management. Lower overhead hay feeders, spread hay out and do not feed hay containing mature seed heads or cheat grass in overhead feeders or round bales. Increase bunk space to decrease direct contact.

4. Ultraviolet light (sunlight). Breed for pigmentation around the eye, consider introducing Brahman influence into the herd and provide shade or tree rows with ample room to prevent overcrowding.

5. Disease management. Isolate infected animals and decrease environmental and nutritional distress. Provide proper vaccinations as recommended by your veterinarian to improve overall animal health.

6. Vaccination. Commercial and autogenous pinkeye vaccines are available. Results reported by producers and veterinarians have been mixed from their use of these products.

“Typically, vaccinations help reduce the incidence, shorten the duration and reduce the severity of cases but cannot guarantee total prevention of an outbreak,” Randle says.

Vaccines obtain the best results when they are specific to the causative agent in the herd and administered prior to infections. Culture, serotyping and sensitivity should be performed to determine the bacterial pathogens and serotypes involved in the outbreak. This will provide information about treatment and the choice of vaccines.

Check with your local veterinarian about the use of these products in a specific geographical area.

7. Maintain current health records. Identify cattle that repeatedly become infected and those that seem more tolerant to infection. This information can help with culling decisions.

OSU extension specialists remind producers a key to prevention is to observe cattle carefully and identify the disease early for effective response to treatment. They also suggest quarantining new purchases.

“Reducing dusty conditions also aids in control,” Randle says. “Cattle often have grass or weed seeds in their eyes, and these materials no doubt irritate the eye and contribute to the development of pinkeye.”

Pinkeye rarely affects just one animal, but spreads throughout the herd.

“According to a 1993 study, costs resulting from decreased weight gain, weaning weight, milk production and treatment were estimated to be $150 million in the U.S. alone,” the OSU fact sheet summarizes. “Although newer figures have yet to be published, it is likely current losses greatly exceed this estimate.”

Your Next Read: Combating Pinkeye: Tips for Detection and Treatment

Success From The Start: Calf Health Starts Before Birth

Tue, 15 Jul 2025 13:11:34 GMT

If a calf struggles during its first 60 days of life, it’s going to carry that through all phases of production. Starting a calf, whether in a traditional beef or beef-on-dairy scenario, the right way is paramount to the lifetime health of that animal.

This is the message stressed by Dr. Taylor Engle, Four Star Veterinary Services, during episode eight of “ The Future of Beef Show ” podcast. He says success starts before a calf is born.

“There are a lot of really good genetics in the beef industry we can use. However, if you put that calf in an environment to fail, genetics does not play a factor,” he says. “We have to do everything right from an environmental piece to maximize the genetic potential.”

Check out the podcast to learn more about these five key messages discussed by Engle and the podcast’s hosts:

Environment matters more than genetics. Engle emphasizes if you put a calf in an environment to fail, genetics won’t save it. Management and early life conditions are critical to an animal’s success.
Calf health starts before birth. Proper care of the cow before calving, quality colostrum and a clean birthing environment are crucial for a calf’s lifetime health.

Engle encourages producers to think about the cow’s condition before, during and after breeding.

“Everyone gets really fired up — and rightfully so — about colostrum. Not all colostrum is created equal,” he says. “It’s what we are doing to set that cow up to have the best colostrum for that calf. Whether it’s beef-on-dairy or native, the right vaccines for the right diseases at the right time matters.”
Communication is key across the production chain. Sharing information about calf health, vaccination history and management practices between different stages of production can significantly improve overall animal performance.

Engle encourages producers to record vaccination and treatment information and then share it. Communicating with the feedyard is important to help the feeder decide on how to treat cattle.
Don’t be quick to treat — understand the root cause. Instead of immediately administering antibiotics, veterinarians should first investigate the underlying management or environmental issues causing health problems.

“We were trained to think it’s a disease, and more often times than not, there is a disease present. But there’s been something along the process where we have stressed that animal and caused disease,” he explains. “We’re always looking at it from an environmental standpoint and a management standpoint — the calf isn’t the culprit. What’s going on? Why did that calf break with respiratory disease? They don’t spontaneously get sick. Something happened. Was it a weather, feed or stressful event?”

He adds management strategies and mentality can be keys to determining the cause of a sickness.

“It’s a hard thing — whether you’re a nutritionist or vet — to have that hard conversation with a producer, be upfront with them and say, ‘It’s something we’ve done,’” he says. “A lot of times, there’s management practices that messed up along the way, and the result is a disease.”

In his practice, he works with the producer to help them understand and recognize the management strategies to improve the outcomes.

“In the beef industry, a lot of the mentality is, ‘We’ve never done it this way,’” he says.
“In comparison, in the poultry and pig industries, producers will say, ‘If it increases my production, I’ll do it.’ They have the mentality of being willing to give something a try to see if it increases health.”

Engle adds, “I always tell producers if you want A results, you got to give A effort,” he explains. “You can’t have a C -plus effort and expect A results.”
Stress management is more important than treatment protocols. Focus on reducing stress and creating optimal conditions for calves, rather than relying solely on medical interventions.

“The calves don’t lie,” Engle says.

He emphasizes the importance of careful observation, advising producers to “read calves every day” and make real-time adjustments.

Beef-on-Dairy Calf Health
Engle also has extensive experience with beef-on-dairy calf management and production and discussed how those animals compare to traditional beef calves, highlighting how multiple touch points and movements bring beef-on-dairy calves unique challenges — including different feeding systems and varied vaccine and management protocols at each location.

As a positive, he says, “In the beef-on-dairy space, we have all the data points, or we have the opportunity to collect all the data points. Then you can start making decisions.”

With this complex — but data-rich — production model, there is significant potential for improving calf health and performance.

Engle challenges producers to think holistically about animal health, management and production.

“It’s not the animal that’s usually causing the problems,” he says in summary. “It’s usually producer’s management or oversight. As farms have gotten bigger, the skill gap as we go higher actually closes. Everybody who has 10,000-head of cattle on feed, or more, probably knows a lot about feeding cattle. But what are you going to do for a competitive advantage that the next feedyard isn’t? I think a lot of that’s looking internally at your management strategies and your consulting team. It’s a team effort to get to where you want to be. Set those goals and look at what you need to do better to be where you want to be in the next five to 10 years.”

The Smell You'll Never Forget: A Calf Infested with New World Screwworm

Thu, 10 Jul 2025 16:41:21 GMT

“The stench…it’s like roadkill stewed in infection,” explains Jose Santiago Gallardo Espinosa, a cattle producer from Chiriqui, Panama, describing an animal that has been infected with New World screwworm (NWS). “You’ll smell it before you see it.”

He goes on to describe the appearance. “That little dehorning scrape you didn’t worry about? Now, it’s a fist-sized hole pulsating with maggots. Not on top, under the skin. Hundreds of cream-colored worms with screw-like spines, eating your cow alive.”

It’s a Plague in Panama

Gallardo is a Panamanian livestock production specialist and animal science professional with a diverse and practical background in cattle production, agricultural policy and international ranch management. He currently serves as the technical assistance team manager at Cooleche, R.L., where he leads strategic initiatives in cattle production and technical outreach.

“⁠This ain’t ‘just flies.’ We’ve buried calves eaten alive in 48 hours,” Gallardo stresses. “Post-calving cows are sitting ducks, I found one last week with maggots deep in her vulva, she was trembling as she tried to nurse her calf.”

An animal health professional treating an animal in Panama that has been infected by New World Screwworm.

(Jose Santiago Gallardo Espinosa)

To catch NWS and stop the spread, Espinosa encourages daily wound checks including navels on newborns, vulvas on fresh cows, sheaths on bulls, branding cuts and tagging nicks. Some red flags include a wound that swells overnight or oozes cloudy fluid and a milk tank mysteriously dropping.

“Treat every scratch like a ticking bomb,” he says adding if you find one with a wound acting a little strange, you should “peel back skin edges, and if you see rice-grain maggots with dark spines — sound the alarm.”

He says more than 6,500 cases have erupted across Panama, marching north through Central America like a plague.

“For years, our U.S.-Panama barrier kept NWS at bay,” Gallardo says. “We’d see maybe 25 cases a year — it was a nuisance, not a crisis. Then 2023 hit, and overnight our pastures became war zones.”

He says the reality in Panama is rainy season is maggot season.

“Here, in Chiriquí’s dairy country, it is the perfect storm,” he says. “Rainy season humidity of 90%, 85°F heat and flies everywhere. A single-infected cow bleeds $10/day in lost milk — its life or death for small dairies.”

NWS in Nicaragua

Ernesto José Sequeira Enríquez, an agronomist from Camoapa, Nicaragua, says NWS was eradicated from Nicaragua in the 1990s. He says he first encountered it during an internship in Brazil where he experienced the serious challenge the fly causes.

“When cases began appearing here again last year, I was able to use what I learned in Brazil to prepare veterinary supplies and train people on prevention and treatment,” he explains.

(Ernesto José Sequeira Enríquez)

He says it’s essential to enforce a daily inspection routine, checking every animal carefully for open wounds.

“When you find an infected animal, you’ll typically see a bleeding wound,” Sequeira says. “If the infestation has progressed, there will be a strong, foul smell due to tissue damage and the presence of larvae.”

He encourages U.S. producers to be prepared with sufficient supplies of veterinary medicines and insecticides for both treatment and prevention and to adjust management practices to reduce risk. For example:

When dehorning, branding or ear tagging, apply insecticide spray to the wound immediately.
Ensure proper care of newborn calves by disinfecting the navel with iodine solution as soon as possible, since that is the most common entry point for infestation.

“Although complete control of screwworm is not possible, taking preventive measures significantly reduces the economic and productivity impact of it,” he says. “Early detection and consistent preventive practices are critical to minimizing losses.”
Sequeira stresses a producer’s eyes and hands are their best tools to fight NSW.

“My warning to U.S. ranchers is this isn’t just a Panama problem,” he summarizes. “Newborn calves are maggot magnets. If you lose one calf to a navel infestation, you’ll never sleep again. Make inspections sacred — no excuses. Report fast and hide nothing.”

It’s Endemic in Brazil

Marcelo Costa is a veterinarian, professor and cattle business consultant in Brazil and Paraguay. In 1999, Costa was taught embryo transfer at Camp Cooley in Franklin, Texas. He then returned to his family’s third generation ranching operation where they started Camp Cooley Brazil.

“I have been dealing with screwworm all my life since it is endemic in Brazil,” Costa says. “Screwworm-infected animals happen all months of the year.”

A wound in the animal skin full of screwworm and new fly eggs in the skin borderline

(Marcelo Costa)

Like others, he has experienced finding infected animals with bleeding, foul-smelling wounds. He says animals show discomfort and may not follow the herd as normal.

“Newborn calves are usually the more attacked category because of the navel’s wet and bloody tissue,” he says. “If a screwworm infects the navel, it may open a door at the site for more severe infections that may cause diarrhea, pneumonia and other diseases.”

Costa stresses how much NWS costs producers beyond animal loss and decreased productivity.

“One of the biggest problems with NWS is the increased labor with vigilance and animal treatment,” he summarizes.

Guatemala Producers Are Learning to Cope with NWS

“Screwworm came to teach us the times are changing, and that any type of production is possible and open to any complication,” says Oscar León, a livestock production specialist and agricultural business administrator from Guatemala City, Guatemala. “Brazil learned how to cope with it, and Guatemala is in the process of it. The U.S. is not exempt from it, unfortunately. But with the adequate measures and prevention techniques, one can learn and teach others. We can make the impact less harmful on our production and wallets.”

(Oscar León)

León currently manages his family’s cattle operations and leads LAVAT S.A., a company that imports and distributes innovative animal health and nutrition products tailored to the needs of the Guatemalan livestock sector.

He explains it is important for producers to look for and treat any open wound or bruise as they are the first indicators.

“If an open wound smells like the scent of rotten meat, you will find the presence of screwworms feeding off live tissue,” he says. “Prevention and early timing are the best ways to treat screwworm. Make sure to take your time, observe your cattle, search for a bruise or wounds and treat them properly.”

He also stresses the importance of making sure everyone who works in the farm or ranch is aware of NWS and knows how to react if an infection is found.

Educating U.S. Producers

Chris Womack, a veterinarian and rancher from San Angelo, Texas, says he remembers helping his dad treat calves with NWS infestations.

“I can still remember the smell,” Womack says. “I thought it was cool because I was a little kid, and we dug maggots out of the calves. I can still smell it like it was yesterday, and it was horrible to look at them.”

Womack shares a historic context of NWS, which he says means “man-eater,” on the “Registered Ranching” podcast with Tucker Brown.

Womack also describes the emotional toll on the producer when faced with NWS.

“If you’re a steward of an animal and it has half of its head rotting off, or its abdomen is a gaping wound because the maggots are eating it up, or it gets in their ear and they’re walking around in circles with brain damage because they got meningitis, well, it’s devastating.”

Womack summarizes NWS isn’t just an agricultural issue, it’s a human health concern. Historical accounts and recent data from Panama show NWS can affect humans, particularly vulnerable populations like homeless individuals or those in areas with limited medical access.

Womack says the experiences with NWS during his childhood is the reason he is a veterinarian today. He says there is a generational ignorance in the U.S. regarding NWS, and that is something he is committed to fixing.

“The only way we can overcome ignorance is education,” he stresses.

Your Next Read: Breaking: Mexican Border Closed Again as New World Screwworm Comes Within 370 Miles of the U.S.

Protect Your Herd: The Signs to Watch for Calf Pneumonia

Wed, 09 Jul 2025 10:52:01 GMT

Pneumonia in young calves is an important contributor to death loss before weaning. Many veterinarians and cattle producers think of post-weaning respiratory disease, also known as Bovine Respiratory Disease (BRD), when they think about pneumonia in cattle; but calves can get pneumonia while they are still suckling their dams.

Bob Larson, K-State veterinarian, says because the risk factors associated with pre-weaning respiratory disease differ from BRD in stocker and feedlot cattle, which is usually associated with commingling and transportation.

“Our understanding of how to prevent and control BRD in post-weaned calves is not sufficient to address pneumonia in suckling calves,” he says. “Several studies investigating calf pneumonia have reported that an average of 3% to 11% of calves are expected to suffer from the disease each year. In addition, nearly 1.5% of calves will die from pneumonia before they reach the age of weaning; which makes it the second leading cause of pre-weaning death with only scours causing more losses.”

The most likely age for calves to be diagnosed with pneumonia is between 70 and 150 days of age.

Larson says cases of pneumonia are most likely to appear in:

Herds that have more cases of calf scours
Herds that bring in nursing calves from outside herds to graft onto cows that lost their calves
Creep-fed calves
Herds that synchronize cows

“Calves born after a difficult birth and calves that failed to consume enough colostrum have been shown to be at higher risk of getting sick and dying before reaching weaning age,” Larson explains.

Veterinarians indicated in a survey that weather, calving in confinement, failing to adequately vaccinate the herd, and nutritional deficiencies were also suspected for contributing to the risk of calf pneumonia.

Signs of Pneumonia

“Many times, the first sign that a herd has a problem is when a calf is found dead,” Larson warns. “Because death in young calves can also be caused by other diseases such as blackleg, digestive tract disease, or trauma, a veterinarian will probably need to examine the dead calf and may need to submit samples to a diagnostic laboratory to identify the cause of death.”

If you find calves that show signs of pneumonia such as rapid breathing, laying down and being reluctant to rise, and having a high temperature should be treated with an appropriate antibiotic after consulting with your veterinarian.

Tips for Prevention

Larson says vaccinating calves against viruses such as bovine viral diarrhea (BVD), infectious bovine rhinotracheitis (IBR), bovine respiratory syncytial virus (BRSV), and bacteria such as Mannheimia haemolytica and Pasteurella multocida may help prevent outbreaks of calf pneumonia or reduce the severity of disease, but we know that a young calf’s immune system is not able to respond as well to vaccinations as an older calf’s.

“Because even a calf with a good immune response can be overwhelmed by a large exposure to germs, a successful plan to prevent disease in young calves needs to involve more than just vaccinations,” Larson adds.

He says the herds that have the best calf health have a short calving season and few heifers and cows experiencing calving difficulty. In addition, try to keep young calves away from mud and other calves as much as possible.

“Cows that calve in good body condition and that are on a good plane of nutrition are more likely to have healthy calves,” Larson says. “The best disease-control strategy is to focus on having good overall health of the cows and calves by meeting the herd’s nutritional needs, providing a good environment and timely use of vaccinations in the cows and calves.”

In summary Larson says, if calves are affected with pneumonia while suckling their dams on summer range, you should be prepared to recognize and treat cases as early as possible with appropriate antibiotics in order to minimize death losses.

Your Next Read — Combating Pinkeye: Tips for Detection and Treatment

Got Foot Rot?

Mon, 07 Jul 2025 10:57:59 GMT

Foot rot is a common disease affecting cattle. The primary agent responsible for foot rot is Fusobacterium necrophorum, a common bacterium of healthy skin. However, it requires an opportunity to invade deeper tissues such as injury or wet skin. This bacterium often acts in conjunction with other bacteria.

Environmental factors play a significant role in the transmission. Moisture, nutrient deficiencies, and injuries from walking on abrasive surfaces can compromise skin integrity, facilitating bacterial invasion. Standing in pens or lots heavily contaminated with mud, feces, and urine softens the skin, increases risk. High temperatures and humidity can also cause the skin to become more fragile, making it more susceptible to infection.

Foot rot can affect cattle of all ages, with increased incidences during or following wet, humid conditions. The first signs include sudden onset of lameness, swelling and redness of the tissue between the claws, and ulcerative type lesions in the interdigital space. The tissue is often necrotic with a characteristic foul odor. Swelling is typically evenly distributed around both digits and the hairline of the hoof, leading to separation of the claws. Affected animals are extremely painful in the affected foot and may also exhibit a loss of appetite.

Diagnosis starts with a thorough examination of the foot. It is important to differentiate foot rot from other conditions causing lameness. Swelling attributable to foot rot involves both claws, whereas other conditions often involve only one. Joint infections, sole abscesses, and sole ulcers may be mistaken for foot rot.

Treatment begins with cleaning and examining the foot. Antibiotics are the primary treatment. Non-steroidal anti-inflammatory products should be utilized for pain relief. Veterinary consultation is necessary in situations where the animal does not respond quickly to the initial treatment as foot rot is likely not the cause of the animal’s lameness. In cases where deeper foot structures are damaged, more aggressive therapy may be necessary.

Foot rot prevention focuses on maintaining interdigital skin health. This includes providing a well-balanced mineral program and minimizing environmental conditions that may cause skin or hoof injury. Preventing cattle from standing in wet, manure-infested areas is crucial. Footbaths may be helpful for animal in confinement. A foot rot vaccine is available that may aid in prevention, but producers should consult their local veterinarian to determine the best options.

Your Next Read: 5 Strategies to Help Cattle Cope with Heat

Protect Your Livestock: Signs of New World Screwworm

Tue, 01 Jul 2025 15:45:15 GMT

Lizeth Olivarez doesn’t know if people will have the stomach to deal with New World screwworm (NWS). She’s a sixth-generation rancher who runs cattle in the U.S. and in Mexico at Las bendiciones Ranch in Realitos, Texas, and Rancho El Cuellareno in Guerrero, Tamaulipas.

Although she hasn’t experienced it herself, she has grown up hearing story after story about NWS from both her grandfather and father who dealt with NWS when the deadly fly struck in the 1960s. With reports of NWS in seven states in Mexico, the U.S. continues to bolster its defenses to keep the pest out.

(USDA)

“The first time around NWS was eradicated by using sterile flies dropped from planes in a box that look like a Big Mac burger box with a target sign on it,” Olivarez says. “The only way to eradicate the NWS is with sterile flies.”

Secretary of Agriculture Brooke Rollins announced a five-pronged plan to combat NWS on June 18 partnering with Mexican counterparts and using this sterile insect technology to stop the spread.

“It’s important to clarify we currently don’t have [NWS] here in the U.S.,” says Russ Daly, Extension veterinarian for South Dakota State University.

He admits it’s a strange name for a fly – New World screwworm – because it makes you think it’s a worm.

“It’s not actually a worm – it’s the larvae of the NWS fly that deposits its eggs in animals,” he explains. “They can get big in size, up to two-thirds of an inch. The first person who described them might have thought they look like little worms. They have ridges that are spiral, and that allows these larvae to burrow down into the animal. That’s how they get their name.”

The NWS fly lays eggs and larvae in open wounds of warm-blooded animals. Daly says NWS’s function is similar (but different) to a maggot. Domestic blow flies lay their eggs on dead tissue. The resulting maggots feed on the dead tissue. The difference with NWS is it lays its eggs on living tissue and will feed on living tissue.

“NWS is not easy to recognize,” Daly adds. “You really need an entomologist to recognize the fly and the larvae. For recognizing a problem in the animal, it might come down to recognizing a larval infestation that is showing up in unusual circumstances.”

(Lori Hays)

It’s Not Just a Cattle Problem
Megan Niederwerder, executive director of the Swine Health Information Center (SHIC), says it’s important to remember this is not just a cattle disease – it impacts other livestock species and humans as well.

(Lori Hays)

“The fly can deposit its larvae in any open wounds as well as surgical sites such as castrations and umbilical sites after a newborn animal is born. It can also deposit its larvae in any mucous membranes,” Niederwerder says. “Keep an eye on non-healing wounds or wounds that have a foul odor or bloody discharge.”

She says the animals often feel discomfort and pain due to this non-healing wound so they may isolate themselves and be off feed.

“It’s really important to stay vigilant as we think about increasing awareness and understanding of what the fly looks like,” Niederwerder says. “We also need to understand what the clinical signs may look like as the introduction and incursions in Mexico have increased the risk for the U.S., too.”

Although the cases in Mexico have been primarily cattle, she notes there have also been cases in pigs, horses, sheep, goats, dogs and even in humans in Mexico.

“We really don’t like to think about that human part of it,” Daly says. “I don’t want to downplay it, but in people, we would certainly know when we have an irritation or when a fly is on us. But we need to think about the people who potentially are debilitated and wouldn’t know they have a fly on them for a long period of time or that something’s wrong.”

Watch Out for the Unusual
Olivarez urges producers to call their veterinarian immediately if they suspect NWS. During the 1960s outbreak in the U.S., she says most ranchers first noticed it around the umbilical cords of newborn calves.

“It affected ranches the most, especially those that had cattle out on the range where you need manpower to monitor for open wounds, cuts or sores of any kind as well as cows with newborns since the fly will attack the umbilical cord,” Olivarez explains.

She says it’s not only important to monitor cattle but also pay attention to wildlife and pets that live on your property since they could indirectly bring NWS.

Daly challenges livestock producers to pay attention to unusual situations. If you have an animal that suddenly has a lot of necrotic tissue that fly larvae (maggots) are trying to clean up, Daly says that’s a sign producers need to take seriously.

(Lori Hays)

“If there isn’t a wound or a very good reason why there would be an infestation of those larvae that should tip off animal owners, caretakers and veterinarians,” Daly says. “There needs to be some sort of break in the skin to attract the NWS fly, but that something can be so minuscule you wouldn’t even notice it.”

He says it could be as small as a bug bite and is often so tiny producers don’t know how the initial entry even happened.

“NWS does its damage by burrowing into living tissue,” Daly explains. “But they can be drawn to the animal through secretions from that minor break in the skin, and then start to invade the living tissue as well. In addition, once the NWS sets up the wound and causes the infestation, normal blow flies then can come in and get in there, too.”

(Lori Hays)

The females lay their eggs very quickly, he adds. It doesn’t take long for the larvae to develop from there. He says the flies like to deposit their eggs on their “victims” in the afternoon.

“They choose this timing because when it cools off at night, it helps the development of the eggs into the larvae,” Daly says. “This all happens within 10 to 12 hours. If you have a fly that gets into a nick on a pig in the afternoon, for example, by next morning, there’s larvae starting to burrow in already.”

The fly has a lifespan of 28 days, Olivarez shared with followers of Texas Farm Bureau on TikTok.

@txfarmbureau Ever heard of the New World screwworm? South Texas rancher Lizeth Cuellar Olivarez breaks down why this tiny pest is a big problem for livestock. #texasfarmbureau #agtok #farmtok #fyp #screwworm ♬ original sound - texasfarmbureau

“During this time, NWS can lay eggs four times and lay 300 eggs each time,” Olivarez says. “If it goes untreated, after three weeks the larvae will fall and convert to a fly that then goes looking for another animal to attack.”

Treatment Tactics Aren’t Pretty
If an animal becomes infested with NWS, treatment is not easy or pleasant. The larvae have to be removed, Daly explains.

“NWS does respond to some insecticides that we would use for show pigs or horses during the summer to keep the flies off,” Daly adds. “But in order to get that animal healed up, the larvae have to be flushed out and removed by a veterinarian. These infestations can lead to secondary infections to worry about. And, if the infestation has gone deep enough, there could be severe muscle damage or damage to other organs that are beyond help.”

Treatment products need to be considered, adds Lisa Becton, assistant director of SHIC. Because of this, wound care is key during NWS infestation.

“If you have animals that have sores, it’s very important to treat that wound,” Becton says. “You may or may not be able to use a sealant, whether that’s iodine or antibacterial. Wound care is very important to help get a wound healing fast, even if you also have to use antimicrobials for an animal to help prevent other infection.”

It is treatable, but NWS is a painful event for animals and humans alike, Becton says. Rapid identification and action are critical.

Stay Alert, But Don’t Panic
Livestock trade and wildlife migrating due to different issues with climate and weather have helped move the infestation further north.

“The flies actually don’t fly that far,” he explains. “They typically fly less than 10 to 12 miles in their life span. So, they aren’t flying over on the wind and getting into these new places. It has more to do with animal movement.”

Fortunately, Daly says NWS is like any other fly in that they need somewhere to overwinter, so they won’t survive freezing temperatures. However, if they moved into this region in June or July, they would have a foothold until the frost.

“When we let our guard down and don’t look for it as much, or don’t use the sterile flies as often, that’s when things fire up again,” Daly says.

He says it’s not time to panic, but it’s important to be observant. The basics of good animal husbandry remain the most important thing for producers to focus on now.

“Sometimes it’s much easier said than done, especially in outdoor raising situations,” Daly says. “From fly control to monitoring animals, the best way to snuff something out like this quickly is good observation and animal care.”

Your Next Read: New World Screwworm: The Billion Dollar Battle at the Southern Border

New World Screwworm: The Billion Dollar Battle at the Southern Border

Fri, 20 Jun 2025 18:27:58 GMT

Nearly 60 years ago, the U.S. eradicated New World screwworm (NWS). Today, the risk of reintroduction is real. So real that Ethan Lane with the National Cattlemen’s Beef Association (NCBA) says it’s not a matter of if NWS will reach the U.S. but when.

“We need to spend $300 million now to save us $8 billion down the line in eradication costs,” says Lane, who serves as the senior vice president of government affairs. “This is a marathon, not a sprint, and it’s going to take years to re-eradicate New World Screwworm and push it back to Panama.”

As the fight to keep NWS out of the U.S. ramps up, the economic impact on ranchers and the industry is top of mind.

“Successfully eradicating New World screwworm from the U.S. in 1966 cost stakeholders’ tens of millions of dollars,” says TR Lansford III, DVM, deputy executive director and assistant state veterinarian with the Texas Animal Health Commission. “The freedom from NWS provides an estimated $1 billion in direct benefits to livestock producers and $3.7 billion in benefits to the general economy annually.”

Financial Impact of NWS On Ranchers
Regular, large-scale outbreaks of NWS started occurring in the U.S. in the 1930s. According to APHIS, producer losses have reached:

1930s and 1940s — $5 million to $10 million per year
1950s and 1960s — $60 million to $120 million per year
1970s — $132.1 million per year (While the U.S. successfully eradicated the devastating pest, there have been outbreaks, primarily in Texas, since then.)

(APHIS)

Experts agree if NWS reaches the U.S., eradication today will be far more expensive due to the size of the cattle herd, speed and distance of cattle movement in commerce, and increased wildlife interfaces.

“Historically it cost tens of millions, and now it’s estimated to cost into the billions of dollars to eradicate this pest if it gets back to the U.S,” Lansford says.

Based on historical data from an isolated outbreak in Texas in 1976, per-head impact reached $452 in today’s dollars, totaling $732 million.

“[NWS] is a highly impactful foreign animal pest because it is expensive and deadly,” Lansford says. “Back in 1935, when screwworms were endemic in Texas, the state lost about 180,000 head of cattle alone in that year.”

Lansford says the industry will see decreased livestock production and increased veterinary services, medication, insecticide, labor and vehicle costs for the inspection and treatment of NWS.

“Infested wounds and/or mucous membranes and lesions created by this pest cause significant distress and damage to an animal, which can lead to chronic conditions making the animal less marketable and less productive in its lifespan,” he adds.

USDA Investment to Fight NWS
The reopening of Moore Air Base in Texas as a sterile fly distribution facility has an estimated price tag of $8.5 million. A brand new production facility, which would take two to three years to build would cost $300 to $600 million, depending on location and resources.

“That doesn’t include what it would cost to continue to operate one of those facilities,” Lansford says. “Certainly, research dollars also need to be spent to develop more effective treatments and other methods and modalities that we can use to help offset not only the infestations, but help prevent those infestations.”

USDA is also investing $21 million in the renovation of an existing fruit fly production facility in Metapa, Mexico, to further the long-term goal of eradicating NWS.

Border Closing Impacts U.S. Cattle Industry
Since May, Agriculture Secretary Brooke Rollins has suspended imports of live cattle, horses and bison from Mexico to keep NWS out of the U.S. Many U.S. cattle feeders depend on Mexican cattle to fill feedlots, especially now when the U.S. cattle inventory is at a 74-year low.

“Mexico exports, on average, 1.2 million head of cattle to the U.S. each year,” says Kathy Simmons, chief veterinarian for NCBA.

Obviously, that number will take a hit with the border closed, but Simmons says even prior to the May 11 suspension, mitigation protocols for NWS, including wound inspections, for cattle from Mexico allowed less than 25% of the usual numbers to cross the southern border each month.

As the U.S. fights to limit the impact of NWS, it’s a long-term battle, reminds Lane with NCBA.

“They’re getting those flies on that leading edge of the incursion. As I understand it, that is slowing the advance in a way that is very good to see,” he says. “The fact is, there are just so many different vectors. There are so many different ways this thing can move north, and we’re going into the hot season where flies thrive. So it’s really about slowing it, about preparing and about making sure we have the resources to meet it and push it back down as quickly as possible. But certainly everyone’s trying to focus right now on trying to hold the line as much as humanly possible.”

As Lansford has come to realize: “This pest will be one that leaves quite a mark on our economy.”

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Beef Producers Be Aware: Dangerous Asian Longhorned Tick Continues Migrating West

Wed, 18 Jun 2025 13:21:51 GMT

The Asian Longhorned Tick (ALHT) poses a serious threat to cattle health. ALHTs carry Theileria, which is a protozoan parasite that infects red and white blood cells. It can lead to anemia and, in some cases, death.

ALHTs are native to eastern Asia, eastern China, Japan, the Russian Far East and Korea but were introduced to Australia, New Zealand and western Pacific Islands. In other countries, it can also be called a bush tick, cattle tick or scrub tick.

In the U.S., ALHT was first detected in New Jersey in 2017. Since then, it has spread to more than 20 states with recent confirmations in Illinois , Michigan and Iowa .

According to USDA’s Animal and Plant Health Inspection Service (APHIS) ALHTs are known to carry pathogens, which can cause disease and may also cause distress to the host from their feeding in large numbers. For example, a dairy cow may have a 25% decrease in milk production after becoming a host.

A female can reproduce without a mate and lay up to 2,000 eggs at a time. This can cause great stress on a heavily infested animal and result in reduced growth and production. A severe infestation can kill the animal from excessive blood loss.

Asian longhorned tick life stages and relative actual size.

(Photos of unfed ticks by Centers for Disease Control. Photos of engorged ticks by Jim Occi, Rutgers, Center for Vector Biology.)

What does it look like?

Unfed ALHTs range from a light reddish-tan to a dark red with brown, dark markings. While the adult female grows to the size of a pea when full of blood, other stages of the tick are very small — about the size of a sesame seed.

Adult females are a grey-green with yellowish markings. Male ticks are rare.

APHIS reports it only takes a single tick to create a population in a new location.

The above photos are of a AHLT engorged (on the left) and an adult AHLT not engorged.

(New Jersey Department of Agriculture)

ALHTs need warm-blooded hosts to feed and survive. They have been found on various species of domestic animals — such as sheep, goats, dogs, cats, horses, cattle and chickens — and wildlife. The tick has also been found on people.

What are the health risks?

APHIS says ALHTs are not known to carry Lyme disease, but they can cause tickborne diseases affecting humans and animals such as:

Rocky Mountain spotted fever
Heartland virus
Powassan virus

APHIS says those diseases have not been confirmed outside of a laboratory setting in the U.S. In addition, U.S. ALHT populations can transmit U.S. Theileria orientalis Ikeda strain (Cattle theileriosis) in the laboratory.

In an Iowa State University release , Grant Dewell, Extension beef veterinarian and associate professor, says cattle affected by Theileriosis will show signs of lethargy, anemia and difficulty breathing. They may develop ventral edema, exercise intolerance, jaundice and abortions.

“Although signs of Theileriosis are similar to anaplasmosis, younger animals and calves often display more severe signs compared to mature cows and bulls,” he says. “Due to anemia from both tick infestation and Theileria, the risk of death can be elevated. If cattle producers suspect either Theileria or ALHT, have a veterinarian collect appropriate samples and submit them to a veterinary diagnostic lab.”

According to an Oklahoma State University press release , under laboratory conditions ALHT is a competent vector of numerous pathogens that can cause disease in humans, including Rickettsia rickettsii (Rocky Mountain Spotted Fever), Heartland Virus and Powassan Virus.

In “ Clinical Infectious Diseases, ” Bobbi Pritt, MD, MSC, with the division of clinical microbiology at the Mayo Clinic in Rochester, Minn., reported a human bite that occurred in New York in 2019. She says though the report of a human bite isn’t surprising, it proves the invasive longhorned tick continues to bite hosts in its newest location.

“This is extremely worrisome for several reasons,” she writes. “One reason is Asian longhorned ticks can carry several important human pathogens, including the potentially fatal severe fever with thrombocytopenia syndrome (SFTS) virus and Rickettsia japonica, which cases Japanese spotted fever. While these pathogens have yet to be found in the United States, there is a risk of their future introduction.”

Also, Pritt says several other human pathogens have been detected in the ticks, but it’s not clear if the ALHT species are able to transmit them to humans. They include Anaplasma, Ehrlichia, Rickettsia, and Borrelia species. Lyme disease is caused by Borrelia burgdorferi bacteria.

She warns the organisms are present in states where ALHTs have been found and that it’s possible the tick — known to be an aggressive biter— might be able to transmit Heartland virus given its close relationship to SFTS virus.

How to Tackle Ticks

According to APHIS, various strategies effectively mitigate tick populations on hosts and in the environment.

Regular tick treatments should be effective against ALHTs. Consult your veterinarian or agriculture extension agent about which products to use.
Check your livestock for ticks regularly.
Safely remove ticks from people and pets as quickly as possible. If you think you’ve found an ALHT, seal it in a zip-top bag and give it to your veterinarian for identification.
Habitat modifications can help prevent ticks on feedlots and pastures. This may include mowing grass, removing trees, reducing shade by thinning trees, understory removal and placing mulch barriers.
Apply acaricide using label instructions to tick habitats, such as woodland edges and grassy patches, during times when ticks are most actively seeking hosts. Although it varies by year, ALHTs are generally active from March to November. Consult your state and local regulations for approved acaricides.

“Cattle producers should aggressively control external parasites this summer,” Dewell summarizes. “Insecticide ear tags alone are not enough to control ticks. Consider incorporating a back rubber or regularly applying a pour-on during the summer. Pyrethroid-based products are also available that include a tick control label. If an increase in tick infestations is observed, an avermectin pour-on may be the best intervention.”

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Two Key Tips to Stop Persistently Infected Calves Before They Start

Tue, 17 Jun 2025 17:32:59 GMT

At first glance, a persistently infected (PI) calf may look just like any other in the herd. But beneath the surface, these calves are silent spreaders, continuously shedding bovine viral diarrhea virus (BVDV) and exposing healthy herd mates to infection.

How PI calves risk herd health
PI calves are animals that become infected with BVDV during their time in utero. When the calf is infected before their immune system is able to recognize the virus as foreign, they can become a PI calf. This enables the virus to live and grow within that calf indefinitely.

“There are many consequences that can stem from a BVDV PI calf,” said Jen Roberts, DVM, Boehringer Ingelheim. “The virus itself does a very good job of suppressing the immune system, and because of that, you may see an increase in the incidence of other diseases, like respiratory disease in calves or mastitis in a milking herd. There can also be significant reproductive repercussions like early embryonic losses, abortion and birth defects. While these concurrent diseases are not necessarily caused by BVDV, the immunosuppressive effects of the virus make animals more susceptible to other illnesses.”

PI cattle can shed BVDV through many avenues, including respiratory secretions that spread the virus through the air of confined spaces, and bodily fluids such as milk, saliva, mucus, urine and manure.

Biosecurity can stop PI cattle from entering the herd
While maintaining a closed herd is the best way to prevent BVDV from establishing itself on your operation, it’s not always realistic. Dairy consolidations, expansions, off-site heifer growing, and even taking animals to shows are all common events for many farms.

“Any time you have cattle leaving the farm and coming back, there’s a chance for them to be exposed to a PI animal and become acutely infected with BVDV,” explained Dr. Roberts. “Even those acutely infected animals can shed the virus for a couple of weeks, and if they come in contact with cows that are at the right point in gestation for the fetus to become infected, it can cause a PI calf to be born.”

Dr. Roberts shares that testing for PI animals, and quarantining any new or returning animals, are great ways to prevent BVDV from finding a long-term home within your herd.

“The acute infection period is very short, usually 10 to 14 days, so if it is possible to quarantine new herd additions, the recommended period of isolation is two weeks prior to commingling with the rest of the herd,” continued Dr. Roberts. “If you’re sending animals to a heifer grower, especially one raising heifers for multiple operations, I always recommend that the calves go to a heifer grower that requires PI testing.”

Prevent PI calves through vaccination
“The most common way BVDV spreads is through PI calves, so it’s also important to develop a targeted vaccination program that prevents BVDV PI calves from being born into your herd,” stressed Dr. Roberts.

Vaccinating cows with a modified-live virus vaccine labeled for BVDV like EXPRESS FPhelps protect their health and reproductive efficiency, and enables them to deliver healthy, PI-free calves. That same pre-breeding vaccine will also help cows produce antibody-rich colostrum to protect calves from BVDV and other respiratory disease threats right after birth.

When a calf is infected with BVDV in utero, it will be born persistently infected and will shed the virus for their lifetime.

(Boehringer Ingelheim)

When building a herd with strong immunity, vaccination shouldn’t stop with the dam. While maternal antibodies offer initial defense against disease, that protection wanes over time, opening the door for a gap in calf immunity. Research has shown that when exposed to a PI calf, 70% to 100% of non-vaccinated or immune-suppressed cattle become infected.¹Fortunately, calves as young as 30 days of age can still generate a strong immune response in the face of maternal antibodies.

In a study, 30-day-old calves, with maternal antibodies present, were vaccinated with a uniquely adjuvanted five-way plus Mannheimia haemolytica modified-live virus (MLV) injectable-vaccine protocol, or an intranasal- and injectable-vaccine protocol. Five months later, both groups were challenged with BVDV Type 1b and M. haemolytica.

Results show that the five-way plus M. haemolytica MLV vaccine protocol provided a stronger immune response against BVDV Type 1b. It also decreased the level of BVDV shedding and kept rectal temperatures lower for several days, compared to the intranasal- and injectable-vaccine protocol.²

Not all respiratory vaccines are the same. Dr. Roberts suggests working with your herd veterinarian to solidify a vaccine protocol that best fits your operation’s needs.

BVDV Type 1b is the leading cause of PI calves
Thirty years ago, the majority of BVDV cases were caused by Type 1a. In more recent years, Type 1b has emerged as the most prevalent subspecies of BVDV in the United States, accounting for roughly 70% of reported cases.³

Viruses often mutate to escape detection by an animal’s immune system. Over time, viral mutations resulting from environmental pressures can lead to changes in the prevalence of viral strains, causing clinical disease.

“The most surprising thing to me about BVDV has been the divergence of the different subspecies over the past 20 to 30 years,” said Dr. Roberts. “We know there are differences in the breadth of BVD protection offered in the commercially available vaccines, and it’s important to reevaluate vaccination protocols periodically as patterns in clinical diseases shift.”

Due to the increasing risk of BVDV Type 1b, Dr. Roberts recommends working with a veterinarian to establish a sound vaccination protocol that includes adequate protection against this particular subspecies.

“It’s important to get at least two — if not three — doses of a modified-live virus vaccine that’s labeled to protect against BVDV 1b administered by the time that calf reaches breeding age,” she pointed out. “We want to make sure that each heifer on the farm has optimal protection prior to breeding, in order to reduce the likelihood that she gives birth to a PI calf.”

While BVDV presents serious challenges, producers have reliable tools like vaccination, testing and biosecurity to manage it. Staying proactive and aware of BVDV impact is the first step in keeping your dairy herd healthy and productive for the long run.

References:

¹Fulton RW, Briggs RE, Ridpath JF, et al. Transmission of bovine viral diarrhea virus 1b to susceptible and vaccinated calves by exposure to persistently infected calves. Can J Vet Res 2005;69(3):161–169.

²Perkins-Oines S, Dias N, Krafsur G, et al. The effect of neonatal vaccination for bovine respiratory disease in the face of a dual challenge with bovine viral diarrhea virus and Mannheimia haemolytica. Vaccine 2023;41(19):3080–3091.

³ Fulton RW, Cook BJ, Payton ME, et al. Immune response to bovine viral diarrhea virus (BVDV) vaccines detecting antibodies to BVDV subtypes 1a, 1b, 2a, and 2c. Vaccine 2020;38(4)4032–4037.

7 Management Practices for BRD Mitigation

Tue, 10 Jun 2025 15:42:53 GMT

The threat of disease-causing bacteria, Mycoplasma bovis, has risen with the increase of comingling in confinement cow-calf operations, according to Vickie Cooper, DVM, a Zoetis beef technical services from Iowa.

M. bovis causes bovine respiratory disease (BRD), targeting beef calves, and leads to irreversible lung damage, mortality, and higher production costs, she adds.

The bacteria are present in the respiratory system of perfectly normal calves but become a bigger problem when calves face stressors such as transportation, commingling, entry into the feedlot, and weather changes, Cooper explains.

Although disease symptoms are similar, the nature of M. bovis makes this pathogen more challenging to detect and treat than other BRD-causing pathogens, she adds.

“Mycoplasma bovis operates a bit like a chameleon,” Cooper says. “The organism lacks a cell wall, and has variable surface proteins, so mycoplasmas can assume many forms and are very good at evading the calf’s immune system.”

The lack of a cell wall also makes treatment more difficult.

“Symptoms must be caught very early for treatment to be effective,” Cooper says. “Mycoplasmas will begin forming communities within the lung, and once those communities are formed, it becomes very difficult for an antibiotic to penetrate the lesion and control the mycoplasmas.”

Management practices for BRD mitigation include:

Minimize commingling where possible and segregate groups based on age, sex and arrival date.
Provide good ventilation and avoid overcrowding.
Maintain proper sanitation of equipment and pens.
Provide adequate nutrition with fresh feed and clean water.
Use low-stress cattle handling techniques.
Provide adequate shelter and avoid dusty environments.
Consult your herd veterinarian for operation-specific strategies.

“We need to focus on doing all of the small things well,” Cooper says.

She encourages producers to work with their herd veterinarian to identify opportunities for improving calf management to limit the risk of M. bovis and other disease-causing pathogens.

Preventing BRD caused by M. bovis through vaccination

Helping to prevent M. bovis infection includes focusing on a calf’s environment and a vaccination program.

“Depending on your management practices and disease prevalence, Protivity may be a great fit for your herd,” Cooper says. “But a solid vaccination program only works if other preventive practices that prioritize calf well-being are also in place.”

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Urgency in Action: We Must Eradicate New World Screwworm

Tue, 03 Jun 2025 13:00:12 GMT

New World screwworm (NWS) continues to threaten the U.S. cattle industry. The potential impact is devastating — the larvae can kill an animal in just four to seven days if not quickly detected and treated.

Colin Woodall, National Cattlemen’s Beef Association CEO, discussed the hurdles of controlling the spread of NSW on the latest episode of the “Unscripted” podcast .

“We have to eradicate it from here,” Woodall stresses. “We need to eradicate it from Mexico. We need to eradicate it from Central America. We need to push this thing all the way back down to South America.”

The NSW fly and its larvae are flesh-eating parasites that pose a significant threat to warm-blooded animals.

“This is not just a cattle issue,” Woodall says. “This could be dogs. This can be cats. It can get into people. So, anything that is warm blooded could be a host for this flesh-eating parasite.”

Woodall says NSW is approximately 700 miles from the U.S. border, having breached the isthmus of Mexico in the states of Oaxaca and Veracruz, adding that Texas is expected to be the first point of entry if the fly continues to move north.

“We’re going to look at every eradication option possible, because we have to get rid of this thing,” he says. “This is not something that can become endemic to United States. We have to eradicate it from here.”

Woodall says the situation has been complicated by cooperation challenges with Mexico. Earlier attempts to transport sterile flies were hindered by bureaucratic obstacles, with planes unable to land and flies dying before deployment. This led Agriculture Secretary Brooke Rollins to close the border, sending a clear signal to the Mexican government about the need for more serious action.

He explains cooperation has reportedly improved, with USDA teams planning to visit Mexico to assess the current situation. The primary strategy for control involves releasing sterile flies into the wild to disrupt breeding and push the population back southward.

Woodall says NCBA is actively working on several fronts to address the threat:

Pushing for the establishment of a domestic sterile fly production facility.
Exploring genetic engineering technologies for fly control.
Investigating treatment options (such as ivermectin) and helping producers understand how to detect and treat potential infections quickly. Woodall says treatment is possible, explaining ivermectin has proven effective in killing larvae and treating wounds. However, early detection is crucial due to the rapid progression of infection.
Conducting education and awareness campaigns to explain the threat without causing panic. He says misinformation has been a significant challenge. A recent false report about NSW in Missouri caused panic and temporarily impacted cattle prices. He adds that while the threat is serious, it’s not a cause for panic.

“While everybody needs to be aware, they don’t need to panic, and that’s the thing we want everybody to understand,” Woodall summarizes.

NCBA is taking an active role in addressing the threat of NSW through education, technological exploration, government collaboration and a clear commitment to preventing its spread.

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Diseases

Breathing Easy: Protecting Livestock from Respiratory Disease

Clearing the Air on Pneumonia

More than Meets the Nose

Prevention Is in the Air

5 Livestock Diseases That Could Impact U.S. Food Security and Economic Stability

Foot-and-Mouth Disease: Trade-Stopping Risk to U.S. Livestock

African Swine Fever: Persistent Threat to U.S. Pork Production

New World Screwworm: Reintroduction Risk and Surveillance Dependence

Highly Pathogenic Avian Influenza: An Ongoing Multispecies Challenge

Porcine Reproductive and Respiratory Syndrome: Endemic Disease, National Cost

Policy and Preparedness Implications for U.S. Animal Health

When Cattle Don't Roam: Uncovering Tick Refuges with GPS, GIS and Modeling

What GPS Tracking Reveals About Cattle Behavior

The Role of Cattle Behavior Models for Predicting Tick Persistence

Why Cattle-Only Tick Control Fails: The Impact of Wildlife and Refugia

A Spatial Approach to Tick Eradication

How to Manage Coccidiosis Risk in Weaned Calves: What Producers Need to Know

The Prognosis

Control and Prevention

Seeing the Whole Elephant: Systems Thinking and Animal Health

Why Looking Closely Isn’t Enough

Systems Thinking: Looking Between the Parts

The Veterinarian as a Systems Navigator

Case Example: Reframing a ‘Simple’ Mastitis Problem

Stepping Back to See the Elephant

Equine Herpesvirus Cases Continue to Climb After Outbreak in Texas

Monitoring for and Limiting EHV-1 Infection

Vesicular Stomatitis Outbreak in Arizona

What is Vesicular Stomatitis?

Controlling Vesicular Stomatitis

The Asian Longhorn Tick Moves West to Kansas

Harness the Full Potential of Your BRD Vaccine with the Right Adjuvant

Maternal Antibodies Can Interfere with Vaccines

Adjuvants Are Critical to Capturing Immunity in Young Calves

Systemic Immunity Builds Long-Lasting Protection

Even the Best Vaccine Needs Correct Timing and Care

Texas A&M Researchers Study Diet’s Impact On Salmonella Prevalence In Cattle

Taking A New Approach

Continuing The Investigation

Bull Tests Positive for Brucellosis: Herd Quarantined and Investigation Continues

Previous Brucellosis Detection

What is Brucellosis?

Emergency Use of Animal Drugs Approved to Combat New World Screwworm

Theileria and the Asian Longhorned Tick: What Beef Producers Need to Know

What We Know about ALHT and Theileria

Best Practices for Prevention

Real-World Experience

Treatment Strategies

Vaccine Developed

Industry Impacts

Risk Factors Associated with BRD in Preweaned Calves

Research Findings

Researchers Offer Advice From New World Screwworm Experience

Reflecting on screwworm infestation threat to endangered Florida deer

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Experts advocate vigilance, reporting suspicious cases

How to report suspected cases

Kansas Beef Producers Beware: A Case of Theileria Found

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Success From The Start: Calf Health Starts Before Birth

The Smell You'll Never Forget: A Calf Infested with New World Screwworm

It’s a Plague in Panama

NWS in Nicaragua

It’s Endemic in Brazil

Guatemala Producers Are Learning to Cope with NWS

Educating U.S. Producers

Protect Your Herd: The Signs to Watch for Calf Pneumonia

Signs of Pneumonia

Tips for Prevention

Got Foot Rot?

Protect Your Livestock: Signs of New World Screwworm

New World Screwworm: The Billion Dollar Battle at the Southern Border

Beef Producers Be Aware: Dangerous Asian Longhorned Tick Continues Migrating West

What does it look like?

What are the health risks?

How to Tackle Ticks

Two Key Tips to Stop Persistently Infected Calves Before They Start

1 Fulton RW, Briggs RE, Ridpath JF, et al. Transmission of bovine viral diarrhea virus 1b to susceptible and vaccinated calves by exposure to persistently infected calves. Can J Vet Res 2005;69(3):161–169.

¹Fulton RW, Briggs RE, Ridpath JF, et al. Transmission of bovine viral diarrhea virus 1b to susceptible and vaccinated calves by exposure to persistently infected calves. Can J Vet Res 2005;69(3):161–169.

²Perkins-Oines S, Dias N, Krafsur G, et al. The effect of neonatal vaccination for bovine respiratory disease in the face of a dual challenge with bovine viral diarrhea virus and Mannheimia haemolytica. Vaccine 2023;41(19):3080–3091.

³ Fulton RW, Cook BJ, Payton ME, et al. Immune response to bovine viral diarrhea virus (BVDV) vaccines detecting antibodies to BVDV subtypes 1a, 1b, 2a, and 2c. Vaccine 2020;38(4)4032–4037.