The Bovine Vet Podcast

The New Rules of Parasite Control

Thu, 07 May 2026 19:35:29 GMT

For decades, parasite control in cattle has followed a familiar script: Treat the whole herd in the spring, treat again in the fall and trust that the job is done. It’s simple, efficient and deeply ingrained in how many operations function.

But that approach is starting to shift.

On the most recent episode of “ The Bovine Vet Podcast ,” Megan Bollin, a technical services veterinarian with Norbrook, and Nancy Jackson, a field veterinarian for the Mississippi Board of Animal Health, describe an industry moving away from routine, whole-herd deworming and toward a more strategic, data-driven approach.

At the center of that shift is a fundamental change in thinking. As Bollin explains, the goal is no longer the complete elimination of parasites but rather smarter management of them.

“Historically, we’ve had the mindset of just getting rid of all the parasites, right? One-hundred percent — we want them all gone. But we’ve got to consider that 90% of the life cycle is in the pasture. So we’ve got to learn to live with these parasites,” Bollin says.

Why Routine Deworming Falls Short

Routine deworming became standard for a reason. It aligned with when cattle were already being handled, minimized labor and offered a straightforward protocol producers could repeat year after year. The problem is that convenience doesn’t always align with biology. Treating cattle when they are easiest to handle may not coincide with the most effective point in the parasite life cycle, which ultimately limits the return on treatment.

“It may be a convenient time when we have them caught, and I know it takes a lot of labor and planning and resources to get those animals through the chute and treat them, but it may not be the most economically beneficial time to treat them if we’re not applying that product at the correct time in the life cycle,” Bollin says.

Because most of the parasite life cycle occurs on pasture rather than in the animal, poorly timed treatments can miss the window where they would have the greatest impact. The result is a system that feels consistent but may not be working as efficiently as intended.

Replacing Guesswork With Diagnostics

As parasite control becomes more strategic, diagnostics are moving from optional to essential. Instead of relying on assumptions or visible signs, producers are increasingly being encouraged to measure parasite burden directly.

Fecal egg count testing provides a snapshot of parasite burden by quantifying the number of parasite eggs present in a manure sample, giving a measurable baseline rather than relying on assumption. Building on that, the fecal egg count reduction test (FECRT) evaluates how well a dewormer is working by comparing egg counts before and after treatment — typically 10 to 14 days later — to determine the percentage reduction. A reduction of around 95% is generally considered indicative of effective treatment, while lower reductions may signal reduced efficacy or emerging resistance.

Together, these tools allow parasite control decisions to be based on data, helping tailor treatment strategies to the specific conditions of each herd rather than applying a one-size-fits-all approach.

“If you’re doing just a straight fecal egg count, it needs to be quantitative. A qualitative test — just saying whether parasites are there or not — is not helpful, because you’re always going to have parasites,” Bollin advises.

Those baseline measurements allow for informed decisions about whether treatment is needed and how well products are performing. Follow-up testing is just as important, helping confirm whether a dewormer is still effective.

Rather than relying on routine schedules, this approach acknowledges that treatment decisions vary from one operation to the next.

“There’s no magic number that says you need to treat at this high of an egg count,” Bollin says. “It’s going to depend on your geography, your herd and your operation.”

That variability is something producers already manage in other aspects of their operation. As Jackson notes, parasite control should be approached with the same level of flexibility.

“Every farm is unique — when they calve, when they wean — so it’s hard to make a cookie-cutter template,” Jackson says.

In many cases, the need for measurement comes down to what isn’t immediately visible. Subclinical parasite burdens can quietly reduce performance without obvious warning signs, making data even more valuable.

Refugia: A Counterintuitive but Critical Strategy

Rather than treating every animal, every time, the concept of refugia encourages leaving a portion of the parasite population unexposed to dewormers. Bollin explains that this approach helps preserve drug effectiveness by maintaining a population of parasites that remain susceptible, rather than selecting only for those that survive treatment.

“Refugia is leaving a percentage of the parasites unexposed to a dewormer. The idea is that resistance is a heritable trait, so we’re trying to dilute those resistance genes and maintain a population of parasites that are still susceptible to the products we have available,” Bollin says.

While it may seem counterintuitive, this strategy reflects a broader shift away from trying to eliminate parasites entirely and toward managing them in a way that sustains long-term control.

Implementing refugia doesn’t mean abandoning treatment. Instead, it means focusing on the animals that benefit most.

“We know that calves are going to be more susceptible, so ideally we want to treat those animals. But those mature cows — if they’re in good condition and have good nutrition — their immune system should be able to suppress those parasites,” Bollin says.

This kind of targeted approach allows producers to use dewormers more effectively while also supporting broader parasite management goals.

Combining Classes to Improve Efficacy

While refugia focuses on preserving a population of susceptible parasites, another strategy aims to improve how effectively treated parasites are eliminated. Combination deworming, or the concurrent administration of anthelmintics from different drug classes, is increasingly being used to improve efficacy in the face of variable parasite susceptibility.

Because these classes act through distinct mechanisms — such as macrocyclic lactones targeting parasite neuromuscular function and benzimidazoles disrupting microtubule formation — using them together can increase overall parasite kill and reduce the proportion of resistant survivors. The benefit becomes clear when considering how efficacy compounds across treatments.

“If you have 100 worms and you go in with a product that has 80% efficacy, you’re left with 20. Then you come in with a second dewormer, also at 80% efficacy, and it kills 80% of those 20. So you go from 80% efficacy up to 96% by using two products with different mechanisms of action,” Bollin explains.

This additive effect can help achieve the reduction typically associated with effective control, particularly on operations where single products no longer meet that threshold. Used alongside approaches like refugia and diagnostic-guided treatment, combination therapy becomes part of a broader strategy aimed at maintaining both short-term efficacy and long-term sustainability.

A More Strategic Future

Taken together, these changes represent a shift away from routine and toward precision parasite management. Instead of relying on fixed schedules, producers are being encouraged to align treatments with parasite biology, use diagnostics to guide decisions and adjust protocols over time.

That shift requires a willingness to rethink long-standing habits. As Jackson points out, progress often starts with being open to change: “We’ve always done it a certain way, but there’s always room to learn and adjust how we’re managing these parasites.”

It also depends on continued collaboration and learning across the industry. Parasite control is not a one-time decision but rather an ongoing process that evolves with new information.

“It’s continual education for both the producer and the veterinarian to understand the life cycle and apply that information to the herd,” Jackson says.

Ultimately, the goal is to move beyond routine and toward more intentional decision-making.

“I think very simply, it’s about not doing it on guesswork like we have been for decades; it’s about using the science and the tools that we have available and being more strategic about how and when we treat,” Bollin says.

Parasites are not going away, but the way they are managed is evolving. Producers who adapt to these new rules will be better positioned to protect both animal performance and the tools they rely on to sustain it.

To hear more from Bollin and Jackson on how deworming strategies are evolving, including where current protocols are falling short, listen to the full conversation on the latest episode of “The Bovine Vet Podcast.”

Precision Genomics: The Veterinarian’s Role in Commercial Herd Rebuilding

Tue, 03 Mar 2026 18:38:03 GMT

With the U.S. beef herd at historic lows , rebuilding is no longer just about numbers. It is about keeping the right females. Today, every retained replacement heifer represents years of genetic influence, input costs and production risk. For the bovine practitioner, this is an opportunity to move beyond traditional “chute-side technician” roles and become a strategic data consultant. Selection is no longer just about phenotype; it is about mitigating biological and economic risks.

The following strategies for precision genomics are pulled from a deep-dive discussion with Dr. Kent Andersen and Dr. Tom Short on The Bovine Vet Podcast . By pairing clinical experience with genomic tools, practitioners can better navigate the current rebuilding phase.

Moving Beyond Visual Appraisal

Visual selection remains a cornerstone of cattle management. Structural soundness, disposition and obvious developmental concerns cannot be ignored. However, phenotype alone does not tell the whole story of an animal’s future productivity.

The Trap of Size: Selecting the largest heifers often inadvertently selects for higher maintenance requirements and increased feed intake.

“Traditionally, commercial cow-calf producers have selected their replacement heifers based on visual appraisal — and perhaps, the ones that are born earliest and just have the look of making a good cow,” says Andersen, director of global beef genetic technical services for Zoetis Animal Health. “Unfortunately, when you select based on looks and size, sometimes you’re picking the biggest ones. So, you’re picking the heifers that may turn out to be the bigger cows that have higher maintenance requirements.”

The Genomic Advantage: Genetic predictions provide insight into metabolic efficiency, fertility, and longevity before a single dollar is spent on development.

“There’s a lot of traits in the unseen world, such as cow fertility, intake, feed conversion, bovine respiratory disease health, that you really can’t gauge by just looking at them,” Andersen says. “The new tools allow the producer to pick heifers that are less risky of dropping out early and maybe not being very profitable.”

Clinical Genomics: Disease Risk and Wellness

One of the more significant recent advancements is the ability to generate genomic predictions related to disease risk, particularly bovine respiratory disease (BRD). Developing those metrics required assembling large populations of cattle with detailed health records and corresponding genotypes. Understanding the value of those predictions requires a clear understanding of heritability.

Heritability vs. Management: Genetics do not replace vaccinations, but they lower the baseline risk. Selecting for higher “Wellness” scores builds a more resilient herd that responds better to clinical protocols.

“Heritability is kind of a term a lot of people don’t understand in a way, but it’s basically just the amount of variation in a trait that we see that’s due to additive genetics, meaning that we can measure it, select for it and improve it,” says Short, associate director in outcomes research with Zoetis Animal Health.

The Data Gap: Historically, commercial heifers lacked the Expected Progeny Differences (EPDs) available to seedstock. Genomic testing (e.g., Inherit Select) bridges this gap, providing EPD-level accuracy on unproven females.

“With this technology, we’re getting genetic predictions in commercial cattle that, if you think about it historically, have had very little, if any, information recorded on them,” Short says. “All the data recording and genetic selection and prediction and everything has really occurred at the seedstock level.”

By combining DNA information with national cattle evaluation systems, commercial heifers can now receive EPDs across a range of economically important traits, from fertility and growth to structural and health-related measures.

Managing Genetic Antagonisms

Selecting for a single trait, such as extreme growth, often comes at a cost to others, such as calving ease or fertility.

“Selecting to increase one trait may actually decrease another, but in an undesirable direction,” Short explains. “That’s where you have to weigh the two traits in an index appropriately, knowing that there’s antagonisms there.”

Economic Indices: Use weighted indices to manage these trade-offs. These tools balance production and maternal performance to ensure overall operation profitability rather than chasing outlier data points.

Precision Culling: Identifying “bottom-tier” genetics early allows producers to divert resources toward high-potential females, optimizing the client’s input costs and long-term sustainability.

The DVM as the “Trusted Adviser”

The veterinarian is often the most influential voice in a producer’s decision-making process, making them the ideal conduit for genomic integration.

“In our interactions with commercial cow-calf producers, it’s almost always the veterinarian that is the most trusted adviser,” Andersen says. “The veterinarian is helping them with their herd health program, so we think it’s a natural fit for the bovine practitioner to also assist with getting DNA collected and using the results.”

Short echoes that sentiment. “Most cow-calf herds that have a valid client-patient relationship with their veterinarian trust them as a resource, and especially when it comes to things like health and genetics, which are more technical aspects of what they have to do in their everyday jobs,” he says.

Workflow Integration: DNA collection via ear punch is easily integrated into routine pregnancy diagnosis, vaccination, or breeding soundness exams.

Consultative Value: By interpreting genomic results, veterinarians can guide mating strategies and marketing decisions—such as selling “value-added” replacements—strengthening the Veterinarian-Client-Patient Relationship (VCPR).

The Economic Reality of Genomic Testing

Early adopters in the commercial space are capturing disproportionate value in a tight market.

“Early adopters are the ones that get the biggest reward,“ Short says. “Not only am I going to select the very best heifers I test for my own replacements, I’ve got a next group here that are pretty good. I’m going to sell them as value-added replacements to my neighbors.”

Genomic testing, often costing between $15 and $40 per head, can lead to significantly higher lifetime returns by ensuring only the most efficient, fertile, and healthy females enter the breeding herd. While visual appraisal and experience are still important, pairing intuition with genomic insight defines the next generation of decision-making.

Summary for the Practitioner

“I think the sail has been set to evolve from real group herd-based to more individual animal-based in our selections, in our matings, in our management protocols, in our days on feed and harvest time protocols,” Andersen concludes. “The individual animal information, I think, paves the way for that.”

As the industry shifts toward individual animal management, genomic data is the next essential “diagnostic tool.” It allows the practitioner to move from managing groups to optimizing individuals, ultimately building a more profitable operation for the client.

To hear more from Andersen and Short on how genomics is redefining the commercial cow-calf industry, including more information on Inherit Select and the newly introduced BRD selection indices, listen to the full conversation on the latest episode of The Bovine Vet Podcast .

10 Cattle Health Advancements That Could Fit into Your Daily Practice

Sat, 14 Feb 2026 14:42:19 GMT

Walking the trade show floor at CattleCon 2026 , the pace of change was hard to ignore. New diagnostics, therapeutics and management tools lined the aisles, each promising sharper decision-making and stronger herd performance. For veterinarians, the challenge is not access to innovation. It is determining which tools will meaningfully improve outcomes and which are incremental updates wrapped in compelling marketing.

Several clear themes surfaced across product categories. Stress mitigation has an increased presence, with companies targeting both behavioral and physiologic responses tied to handling, transport and management changes. The focus is not simply on calmer cattle, but on stabilizing performance and reducing downstream setbacks. At the same time, diagnostics continue shifting closer to the point of care. More products are designed to deliver actionable information at the chute or pen, narrowing the gap between testing and intervention. Efficiency, both in labor and procedure, is increasingly part of the value proposition.

Products centered on rumen health and calf resilience lean into microbiome research and bioactive supplementation. The goal is targeted support during predictable risk periods such as scouring or transport, when animals are most vulnerable to performance losses.

Diagnostic platforms reflected a similar push toward earlier insight. Rapid pregnancy testing capable of producing results from two drops of blood at 28 days post-breeding drew attention from producers seeking tighter reproductive timelines. Expanded chute-side and ear notch options for BVD detection reinforce ongoing efforts to identify and manage infection quickly. Genomic testing for conditions such as bovine congestive heart failure signal broader investments in identifying risk before clinical signs emerge.

Conversations around treatment remained grounded in antimicrobial stewardship. Research examining first-treatment strategies for bovine respiratory disease following metaphylaxis highlighted continued industry focus on timing, drug selection and responsible use. The emphasis was not on introducing an entirely new class of drugs, but on refining how existing therapies are deployed.

Not all innovation centered on pharmaceuticals or biologics. Ergonomic ultrasound tools designed to reduce shoulder strain, along with battery-powered vaccination devices that support multiple routes of administration, reflect growing recognition that practitioner durability and injection accuracy influence herd-level outcomes.

For veterinarians who want a deeper look at how these products are positioned and what the companies behind them say about real-world application, the full conversations from the trade show floor are available in Episode 2 of The Bovine Vet Podcast . Listening offers additional context around development, intended use cases and how these tools may fit into day-to-day practice.

Featured in this episode of The Bovine Vet Podcast :

CattleZen from Solvet: A topical pheromone solution that helps calm down cattle for reduced stress and easier handling. (Guest: Steve Schram)
Bovacillus from Novonesis: A probiotic with two Bacillus strains to support rumen and lower gut health. (Guest: Greg Eckerle, PhD)
Early Pregnancy Rapid Test from Central States Testing: This gives results with only two drops of blood and has been shown to be 99.5% accurate at 28 days post-breeding. (Guest: Dustin Hessman)
Prozap from Neogen: This line up is for external parasites, including lice and flies. The company’s genomics testing for bovine congestive heart failure is also discussed. (Guest: Kenton Carlson)
FerAppease from FERA: This product is a synthetic analogue of the maternal bovine appeasing substance to help animals deal with management and physiological stressors. (Guest: Rodrigo Bicalho, DVM)
Reproarms from ReproScan: These extension arms reduce shoulder and arm strain and allow for safer and faster pregnancy diagnosis and fetal aging. (Guest: Elle Terhaar)
Replenish Ab+ and BovAlign from TechMix: Replenish Ab+ is an electrolyte with maternally derived bioactives to help support calves during scouring, while BovAlign is a nutrient-dense liquid designed to help combat the stresses associated with transport. (Guest: Nathan Upah)
BVD testing from Idexx: From chute-side blood testing to ear notch tests, there are multiple options for detection of the virus. (Guest: Mike Ray)
BRD research from Virbac: This investigates the use of tulathromycin for the first treatment of BRD following metaphylaxis treatment with the same drug. (Guest: Jessica Newberry, DVM)
Power-VACC from Henke-Sass Wolf: This battery-powered vaccination device supports intradermal, subcutaneous, intramuscular and nasal administration of fast and accurate injections. (Guest: Marius Leyhausen)