The first positive case of West Nile Virus in an Ohio horse has been confirmed in 2016.

Testing on samples taken from a seven-year-old Standardbred in Tuscarawas County confirmed the positive WNV diagnosis to the Ohio Department of Agriculture September 12. The horse’s veterinarian first examined the animal on August 29. The animal was euthanized after exhibiting significant clinical signs, including shaking, agitation and thrashing. The horse had not been vaccinated.

West Nile Virus is transmitted to horses via bites from infected mosquitoes. Clinical signs for WNV include flulike symptoms, where the horse seems mildly anorexic and depressed. Changes in mentality, drowsiness, driving or pushing forward (often without control) and asymmetrical weakness may be observed. Mortality rate from WNV can be as high as 30-40 per cent in horses. Infection with WNV does not always lead to signs of illness in people or animals. WNV is endemic in the United States and Ohio has reported three positive cases in horses each of the last few years.

“This incident in Tuscarawas County should serve as an alert to all horse owners to vaccinate their animals against West Nile Virus,” said State Veterinarian Dr. Tony Forshey. “Vaccines are a proven and effective prevention tool and I encourage all owners to talk to their local vet for options and advice on how to keep their animals healthy.”

In addition to vaccinations, horse owners also should work to reduce the mosquito population and eliminate possible breeding areas. Recommendations include: removing stagnant water sources; keeping animals inside during the bugs' feeding times, which are typically early in the morning and evening; and using mosquito repellents.

(Ohio Department of Agriculture)