Horse put down after West Nile diagnosis

Posted at 2:30 p.m. on July 24, 2017

The Brillion News

MADISON – An unvaccinated yearling Standardbred cross gelding from Clark County is the first reported Wisconsin horse to have become infected with West Nile Virus (WNV) and euthanized this year.

“It’s been a very wet summer so far this year, which contributes to a growing mosquito problem,” said Dr. Julie McGwin, equine program veterinarian for the Wisconsin Department of Agriculture, Trade and Consumer Protection.

West Nile Virus is caused by a virus transmitted by mosquitoes, and may cause encephalitis, or inflammation of the brain, and is fatal to horses in 90 percent of cases. Symptoms in horses include depression, appetite loss, drooping eyelids and lower lip, fever, weakness, twitching, paralysis or lack of coordination, aimless wandering, circling and blindness.

The virus is not contagious between horses, but can be carried by mosquitos from an avian, or bird, host to horses and humans. While humans may also be infected by WNV, the virus does not pass directly between people and horses.

Mosquitoes biting warm-blooded animals is the only route of transmission. Horses that have not already been vaccinated this year for WNV or other mosquito-borne diseases are at greater risk.

“Those horse owners who have vaccinated should check with their veterinarians to see whether a booster is appropriate,” McGwin said.

Horses that have never been vaccinated will need two doses two to four weeks apart, and the vaccine will take at least two weeks to build up enough antibodies to protect them. Vaccines will not protect horses that have already been infected when they receive the injections.

Vaccines are available that protect against WNV and another common mosquito borne disease, Eastern Equine Encephalitis (EEE).