As fall and winter approach, cattle producers face the annual rise in bovine respiratory disease (BRD) risk. Cold weather brings sharp temperature swings, increased shipping, and co-mingling, all stressors that compound the natural anatomical vulnerability of a cow’s respiratory tract.
Because BRD and the tools used to combat it are constantly evolving, relying on last winter’s strategy might leave your herd vulnerable.
“No matter the circumstances, BRD requires a strategy each year,” says Dr. Ron Tessman, veterinary technical consultant for Elanco. “We are constantly learning about this disease, how it has evolved, and how we can protect our cattle.”
1. Look Beyond the Vaccine: Holistic Management
While vaccine protocols are top of mind when BRD is mentioned, a complete defense goes beyond a vaccination plan alone. “Cattle are anatomically predisposed to respiratory disease. Relative lung capacity and specific cellular-level features of the bovine respiratory tract contribute to a higher risk of bacterial pneumonia compared with other species,”¹ says Dr. Ron Tessman.
Managing BRD risk requires optimizing everyday management factors that build immune defense ahead of cold-weather challenges:
- Balanced Nutrition: Ensure adequate levels of essential micronutrients, such as copper, zinc, selenium, and manganese, which serve as vital cofactors for immune enzymes and overall immune function.
- Water Quality Testing: High iron or sulfate concentrations in water can bind key micronutrients, creating functional deficiencies in otherwise well-fed cattle.
- Proper Handling: During transport, cattle may have reduced feed and water intake, exposure to temperature fluctuations, and contact with unfamiliar animals, increasing pathogen exposure and immune stress. Be aware of these shifts and help animals minimize stress.
- Responsible Stewardship: Use health tools appropriately to preserve their effectiveness. “We want to prevent resistance development in target bacteria while treating cattle at the appropriate time with the optimum dose to get the most effectiveness out of an antimicrobial,” Tessman says.
2. A Moving Target: Evolving Biology and Antimicrobials
The options available to manage and treat BRD have shifted over time, driven by shifts in bacterial susceptibility and scientific innovation. Early therapies relied on broad options like penicillin, sulfa, and oxytetracycline. These required consecutive daily administration and were rarely tailored to specific bovine pathogens.¹ From there, the introduction of long-acting oxytetracyclines improved convenience. However, repeated exposure to the same antimicrobial class led to shifting bacterial susceptibility in many herds.² To address these gaps, researchers developed classes like macrolides, florfenicol, and fluoroquinolones specifically engineered to concentrate in lung tissue and target primary respiratory pathogens.
3. Navigating a New Landscape
In a market where options exist, antimicrobial selection should be deliberate and evidence-based after clinical options, treatment history, and therapeutic objectives are evaluated.
Fluoroquinolones, for example, differ from other antimicrobials in speed and mechanism. “A fluoroquinolone requires a short time at an appropriate concentration to have the bactericidal killing effect needed to successfully treat BRD,” Tessman says.
A recent advancement in this class is Pradalex® (pradofloxacin injection), an innovative third-generation fluoroquinolone for BRD treatment in cattle intended for slaughter (beef calves 2 months of age and older, growing beef steers, growing beef heifers, and beef bulls intended for slaughter), and in cattle intended for breeding less than 1 year of age (replacement beef and dairy heifers less than 1 year of age and beef and dairy bulls less than 1 year of age).
Pradalex is concentration-dependent utilizing two distinct mechanisms to kill bacteria before they can multiply.
“Pradalex is a great tool that we can add to our antimicrobial toolbox for BRD treatment,” Tessman says. “Pradalex is a treatment-only product used for BRD in cattle only after consideration of other non-fluoroquinolone therapeutic options. If we have animals at high risk in need of a control protocol, other products in the macrolide class could be used to control BRD and hopefully prevent an outbreak.”
4. Execution Matters: Precision Dosing
Even advanced antimicrobials will underperform if timing, dosing, or execution is inconsistent. Accurate weight estimation is critical to prevent under-dosing, which directly accelerates antimicrobial resistance. While running every animal across a scale isn’t always practical in commercial settings, precision still matters.
“It’s incumbent on us as producers and veterinarians to have an idea of what animals weigh and be able to assess that accurately,” Tessman says. “We don’t want to shortchange that animal, because providing a lower dose of any antimicrobial may in and of itself drive resistance development. Making informed decisions optimizes our therapeutic protocol and the response we get from available antimicrobials.”
1Morter RL, Boyce JR, Amstutz JE. Treatment of bovine respiratory disease with erythromycin and amoxicillin. Bov Prac. 1986. Nov (21):62-64.
2Holschbach CL, Aulik N, Poulsen K, Ollivett TL. Prevalence and temporal trends in antimicrobial resistance of bovine respiratory disease pathogen isolates submitted to the Wisconsin Veterinary Diagnostic Laboratory: 2008-2017. J Dairy Sci. 2020. Oct;103(10):9464-9472.
INDICATIONS FOR PRADALEX
Pradalex is indicated for the treatment of bovine respiratory disease (BRD) associated with Mannheimia haemolytica, Pasteurella multocida, Histophilus somni and Mycoplasma bovis in cattle intended for slaughter (beef calves 2 months of age and older, growing beef steers, growing beef heifers, and beef bulls intended for slaughter), and in cattle intended for breeding less than 1 year of age (replacement beef and dairy heifers less than 1 year of age and beef and dairy bulls less than 1 year of age). Not for use in cattle intended for breeding 1 year of age and older (replacement beef and dairy heifers 1 year of age and older, beef and dairy bulls 1 year of age and older, and beef and dairy cows), beef calves less than 2 months of age, dairy calves, and veal calves.
IMPORTANT SAFETY INFORMATION FOR PRADALEX CAUTION: Federal law restricts this drug to use by or on the order of a licensed veterinarian and prohibits the extra-label use of this drug in food- producing animals. To ensure responsible antimicrobial drug use, use of pradofloxacin should be limited to treatment of bovine respiratory disease (BRD) in cattle only after consideration of other non-fluoroquinolone therapeutic options. Not for use in humans. Keep out of reach of children. Avoid contact with eyes and skin. Individuals with a history of hypersensitivity to quinolones should avoid this product. Not for use in animals intended for breeding greater than 1 year of age. Not for use in beef calves less than 2 months of age, dairy calves and veal calves; a withdrawal period has not been established for this product in pre-ruminating calves. Quinolones should be used with caution in animals with known or suspected central nervous system (CNS) disorders. Mild to moderate inflammatory changes of the injection site may be seen in cattle treated with Pradalex. Pradalex has a pre-slaughter withdrawal time of 4 days for cattle. See package insert for additional safety information. Pradalex, Elanco and the diagonal bar logo are trademarks of Elanco or its affiliates. © 2026 Elanco. PM-US-26-1756
