Officials Confirm West Nile Virus in Ohio Horse
On Oct. 24, the Ohio Department of Agriculture confirmed that an unvaccinated 6-year-old Quarter Horse gelding from Fulton County tested positive for West Nile virus (WNV).

The gelding began experiencing clinical signs of fever, muscle fasciculations (twitching), and weakness on Oct. 22. Jeff R. Hayes, DVM, of the Ohio Animal Disease Diagnostic Laboratory, in Reynoldsburg, said the horse was discharged from the Ohio State University College of Veterinary Medicine on Nov. 5 and is recovering.

This case marks Ohio’s third WNV confirmation for 2019. The first two cases occurred in September in Stark and Morrow counties.

About West Nile Virus

WNV transmission occurs when infected mosquitoes feed on animals, as well as humans, after having fed on infected birds.

Clinical signs of WNV in horses include:

  • Mild anorexia and depression;
  • Fine and coarse muscle and skin fasciculation;
  • Hyperesthesia (hypersensitivity to touch and sound);
  • Changes in mentation (mentality), when horses look like they’re daydreaming or “just not with it”;
  • Occasional drowsiness;
  • Propulsive walking (driving or pushing forward, often without control);
  • Spinal signs, including asymmetrical weakness; and
  • Asymmetrical or symmetrical ataxia (incoordination).

West Nile virus has no cure; however, some horses can recover with supportive care. Equine mortality rates can reach 30-40%. The American Association of Equine Practitioners includes WNV as one of the core diseases all horses should be vaccinated against at least annually.