Has Your Horse Been Vaccinated?

As we get into the summer months and see higher temperatures, it’s inevitable that insect pests, such as mosquitoes will be out looking to snack on the blood of horses, humans, and other animals alike. Mosquitoes should be a great concern to horse owners since these insects carry and transmit potentially lethal diseases such as EEE (Eastern Equine Encephalitis) and WNV (West Nile Virus). An unvaccinated horse can show signs of these diseases 5 to 15 days after being bitten by an infected mosquito. Symptoms of WNV include fever, weakness or paralysis of hind limbs, impaired vision, head pressing, seizures, and aimless wandering. Typical symptoms of EEE include: muscle spasms, difficulty swallowing, paralysis, staggering, aimless wandering, lack of coordination, and eventually death. Historically, most cases of WNV and EEE in NC occur in July and August. If you haven't already, now is the time to get your horses vaccinated. 

 

There is no cure for either of these diseases and mortality rates range from 30 percent for WNV and over 90 percent for EEE. Unfortunately, horses that contract EEE are often euthanized. This stresses the importance of having your horse vaccinated annually by a large animal veterinarian. Horse owners should talk with their veterinarians about establishing a vaccination schedule to protect horses from these mosquito-borne diseases as well as other diseases, such as rabies. Birds, equines, and humans can become infected from a bite by a mosquito carrying the diseases, but there is no evidence that horses can transmit the viruses to other horses, birds, or people through direct contact.

  

There are also some cultural practices horse owners can also utilize to help curb mosquito populations. Mosquitoes can breed in any area of stagnant water that lasts for more than four days, so when possible, remove any source of standing water to minimize their breeding areas. This practice can decrease the chances of exposing animals to both EEE and WNV. Some other management practices such as keeping horses stalled at night, running barn fans, and turning off lights after dusk can also help reduce exposure to mosquitoes. Providing protective gear such as fly sheets and masks can also help deter mosquitoes and other insects from irritating horses, especially at night. Certain insect repellants, containing pyrethrins can be effective if used according to the manufacturer’s instructions. Many of these sprays only offer temporary relief so it is important that horse owners manage mosquitoes and other insects using an integrated approach.

Now is the time to get your horses vaccinated. Although there are few, most cases of EEE and WNV in North Carolina usually occur from June through August. If you think your horse or other equine animals may have contracted EEE or WNV contact your veterinarian immediately.