Remember WNV, EEE in Horses' Spring Vaccines

With more than 600 cases of equine West Nile virus (WNV) and more than 200 cases of Eastern equine encephalitis (EEE) reported in 2012, it was one of the worst years on record for these mosquito-borne diseases. Besides the alarming number of equine cases, more than 5,000 cases of WNV were reported in humans, resulting in 243 deaths. According to the Centers for Disease Control and Prevention, this was the highest on record since 2003.

“Horse owners can become complacent when it comes to diseases like West Nile virus because if they haven’t seen it in their area recently, they simply don’t think it will happen to their horses,” says Hoyt Cheramie, DVM, MS, Dipl. ACVS, manager of Merial’s Large Animal Veterinary Services. “But what we saw in 2012 is that although the number of cases had declined during the past several years, it only takes one heavy mosquito season for the numbers to jump back up to record levels.”

The best way to help protect horses from mosquito-borne diseases is to vaccinate, adds Cheramie. “It simply isn’t worth taking a chance when it comes to diseases like West Nile virus and Eastern equine encephalitis,” he says. “Both of these very preventable diseases have effects that are devastating for the horse and the horse owner.”

As the spring vaccination season approaches, horse owners should consider including WNV and EEE vaccinations in their schedules.

While vaccination is the best way to help protect horses from diseases such as WNV and EEE, staying informed about the threat of equine diseases is also helpful. Merial’s Outbreak Alert program is a tool horse owners can use to evaluate potential disease risk, especially when traveling.

“A horse can be just one mosquito bite away from becoming infected with the West Nile or Eastern equine encephalitis virus,” says Cheramie. “Likewise, a horse can be just one raccoon or skunk bite away from becoming infected with rabies. When horse owners recognize these diseases may exist right in their own backyards, it helps them realize the cost of vaccinating is a small price to pay for the health of their horses and peace of mind.”

As always, horse owners should work in conjunction with their veterinarians when determining a vaccination schedule. According to the American Association of Equine Practitioners guidelines, horses should receive at least five core vaccinations, which include protection against tetanus, EEE, Western equine encephalitis, WNV, and rabies. Other vaccinations are given based upon a horse's individual risk level, which should be determined in conjunction with a veterinarian. Common risk-based vaccines include Potomac horse fever, strangles, rhinopneumonitis, and equine influenza.

“Horse owners have made significant investments in their horses, financially, and emotionally,” says Cheramie. “Helping protect their health and well-being with an appropriate vaccination schedule is the best decision when the alternative is to cope with losing a horse or treating a horse for a preventable disease.”

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