A recent survey of American Association of Equine Practitioners (AAEP) members revealed that many horse owners underestimate infectious disease risks and only take an average or below-average level of biosecurity precautions.¹

This presents significant challenges in managing disease outbreaks, especially as the spring season unfolds. Experts caution that equine activities are at risk, as evidenced by recent outbreaks of equine herpesvirus myeloencephalopathy in the U.S. and Europe and regional outbreaks of equine herpesvirus-1 in the U.S. Event facilities are particularly susceptible to infectious disease outbreaks, with a 60% risk compared to 47% in resident environments.

“We’re entering the busiest time of the year for equine activity, and robust biosecurity plans are essential to prevent disruptions,” says Bryant Craig, DVM, an equine technical services veterinarian for Merck Animal Health. “For those traveling or managing busy farms, it’s vital that they vaccinate and follow good hygiene practices like disinfection and using personal buckets on the road.”

The survey builds on a 2023 survey of horse owners, where researchers sought to gain a better understanding of owners’ knowledge and awareness of biosecurity practices for preventing infectious disease in the United States.² Findings from the owner survey corroborate veterinarians’ impressions:

• Biosecurity awareness among owners is inconsistent. Only 54.2% of facilities have a plan for isolating sick horses.
• Owners underestimate the risk. Over 90% of owners perceived low-to-moderate disease risk from mingling at events.
• Gaps in biosecurity practice. Actions like isolation of sick horses (59.6%) were practiced more than proactive measures like temperature checks (2.5%).

“The goal of biosecurity is to quickly identify the cause of an infectious disease and take steps to prevent its spread,” says Nathaniel A. White, DVM, MS, DACVS, Equine Disease Communication Center director. “It is important to comply with a veterinarian’s recommendations for isolation and treatment, particularly when horsestravel and have contact with new horses.”

Keep It Simple

Even small changes in management and preparation can significantly impact horse health and safety. Implementing straightforward practices not only helps prevent disease spread but also ensures the continuity of equine events and plans. Equine veterinarians surveyed recommend focusing on the following high-priority biosecurity measures:

1. Isolate sick horses. Adequate distance between sick and healthy horses is critical to prevent disease spread. Identify a location where this is possible.
2. Isolate new horses. Set up designated areas for new horse arrivals to monitor and mitigate risks.
3. Monitor temperature. Daily temperature checks, particularly during travel, can help detect disease earlier.
4. Initiate diagnostics when fever is detected. Many infectious respiratory diseases can present with similar clinical signs, so it is important to identify the root cause of the fever to allow for accurate treatment and effective disease management.

White and his team of researchers also highlight a need for greater understanding and awareness among the horse-owning community of the risks of horse mingling, event entry requirements such as vaccination and health certificates, and the creation of biosecurity plans for facilities and events where horses co-mingle.

Tools and Tech to Make Biosecurity Easier

Temperature-sensing microchips, like Bio-Thermo^®, offer dual benefits: reliable identification and efficient temperature monitoring with just a scan. This digital approach to routine temperature monitoring is faster, safer, and less stressful for horses while reducing the need for handlers to directly contact sick animals.

Proper disease management begins with understanding what’s infecting horses. The Equine Respiratory Biosurveillance Program has tracked viral and bacterial respiratory pathogens across the U.S. for 17 years, providing crucial disease insights. In partnership with University of California, Davis, Equine Infectious Disease Research Laboratory, the program delivers rapid test results that enable prompt treatment decisions and curb further disease spread.

The Equine Disease Communication Center provides real-time disease alerts and information to help preventand mitigate equine infectious diseases, including comprehensive biosecurity resources.

“The goal is to make biosecurity easier by taking small, incremental steps,” adds Craig. “We’re all in this together—a close partnership between veterinarians and horse owners will help ensure time in the saddle isn’t cut short by contagious disease.”

Horse owners are urged to talk to their veterinarian about customized biosecurity recommendations. Learn more about trending infectious disease threats and biosecurity through the Equine Respiratory Biosurveillance Program and the Equine Disease Communication Center.

About Merck Animal Health

At Merck, known as MSD outside of the United States and Canada, we are unified around our purpose: We use the power of leading-edge science to save and improve lives around the world. For more than a century, we’ve been at the forefront of research, bringing forward medicines, vaccines, and innovative health solutions for the world’s most challenging diseases. Merck Animal Health, a division of Merck & Co., Inc., Rahway, N.J., USA, is the global animal health business of Merck. Through its commitment to The Science of Healthier Animals^®, Merck Animal Health offers veterinarians, farmers, producers, pet owners, and governments one of the widest ranges of veterinary pharmaceuticals, vaccines, and health management solutions and services as well as an extensive suite of connected technology that includes identification, traceability, and monitoring products. Merck Animal Health is dedicated to preserving and improving the health, well-being, and performance of animals and the people who care for them. It invests extensively in dynamic and comprehensive R&D resources and a modern, global supply chain. Merck Animal Health is present in more than 50 countries, while its products are available in some 150 markets. For more information, visit www.merck-animal-health.com and connect with us on LinkedIn, Facebook, X (formerly Twitter), and Instagram.

References

• 1. White, N, Flynn, K, Pelzel-McCluskey, A. Assessment of Biosecurity for Equine Infectious Diseases in Veterinary Practice. AAEP Proceedings, vol. 70, 2024, pp. 343.
• 2. White, N, Pelzel-McCluskey, A. Cross-Sectional Survey of Horse Owners to Assess Their Knowledge and Use of Biosecurity Practices for Equine Infectious Diseases in the United States. Animals 2023, 13, 3550. https://doi.org/10.3390/ani13223550

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