Is it Too Late to Vaccinate my Horse?

Is it Too Late to Vaccinate my Horse?

Life-threatening diseases are out there, and the best way to help protect your horse is to vaccinate.

Photo: Anne M. Eberhardt/The Horse

April Knudson, DVM, is an equine specialist with Merial Veterinary Services. She has a special interest in equine gastrointestinal health, infectious disease, and lameness. She holds a doctor of veterinary medicine from the University of California-Davis. Here, she answers a question about vaccinating for common equine diseases.

Q. I've heard so many reports of mosquito-borne equine diseases this year but haven't vaccinated my horse yet. Is it too late?

A. This year has been record-breaking in terms of both West Nile virus (WNV) and Eastern equine encephalomyelitis (EEE). As of early September, the USDA Animal and Plant Health Inspection Service (APHIS) had reported 181 equine cases of WNV in 33 states and 112 equine cases of EEE. Nationwide, the number of WNV cases reported in all species (mosquitoes, sentinels, humans, and horses) is the highest it has been since 2004. These life-threatening diseases are out there, and the best way to help protect your horse is to vaccinate.

Even if you haven't stayed current with your vaccination schedule, it isn't too late. But be sure to talk to your veterinarian about using a vaccine that is fast-acting.

In the case of WNV in particular, recombinant vaccines have been proven to be very effective in providing protection, even after a single dose. In one study, onset of immunity occurred in just 26 days after the initial dose. This quick immune response is important if your horse hasn't already been vaccinated.

Since the best way to help protect your horse is to vaccinate, do it as quickly as possible. Both WNV and EEE can be life-threatening, with 33% of the horses that show clinical signs of WNV ultimately dying or being euthanized and 90% of those that show clinical signs of EEE dying.

Horse owners should also remain aware of potential threats to equine health present in their communities. Merial's free Outbreak Alert program tracks reported cases of WNV, EEE, Western equine encephalomyelitis, equine herpesvirus, rabies, equine influenza, and Potomac horse fever around the country. Those who have signed up for the service receive texts and/or email messages notifying them of confirmed disease threats in their areas. Owners who travel with their horses can enter multiple ZIP codes in the site's search field to help them stay abreast of disease threats throughout the country. There are also veterinarian-exclusive features available, including printable materials veterinarians can share with their clients

About the Author


Stay on top of the most recent Horse Health news with FREE weekly newsletters from Learn More

Free Newsletters

Sign up for the latest in:

From our partners