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