West Nile virus is transmitted to horses via bites from infected mosquitoes. | Photo: G. Bohne/Wikimedia Commons

The Maine Department of Agriculture, Conservation, and Forestry announced Sept. 14 that a York County horse has tested positive for West Nile virus (WNV). This is the first confirmed case of WNV in Maine horses on record.

The horse began exhibiting neurologic signs of disease last week and is currently undergoing supportive veterinary care. The horse was not vaccinated against the disease.

“WNV and Eastern equine encephalitis (EEE), which are carried by mosquitoes, are viral diseases that cause similar signs, and are often fatal in unvaccinated horses,” said Michele Walsh, DVM, Maine state veterinarian. “Both viruses can affect human beings if they are bitten by mosquitoes that carry the viruses. People cannot acquire WNV or EEE infection from sick animals, only from the bite of an infected mosquito