West Nile virus is transmitted to horses via bites from infected mosquitoes. | Photo: iStock

On Oct. 29 the Equine Disease Communication Center (EDCC) reported that the Ohio Department of Agriculture (ODA) has confirmed five more cases of equine West Nile virus (WNV). Officials have now confirmed 48 cases of WNV in Ohio horses so far this year—more than triple the number of cases confirmed last year.

According to the ODA and EDCC:

A 4-year-old Thoroughbred gelding from Cuyahoga County developed clinical signs on Oct. 7. His trainer went to retrieve the horse from its stall and noticed it was lame on its right side. The track veterinarian responded and noticed that it was non-weightbearing with a fever of 102.4 degrees Fahrenheit. The veterinarian suspected a high fracture, but the radiograph was negative. The horse’s clinical signs progressed to a head tilt and muscle fasciculations (involuntary twitching) in the neck and shoulders, and eventually the horse went down. He was euthanized and brought to the ODA for a necropsy. After determining that brain tissue was negative for rabies, PCR assay at the ODA’s Animal Disease Diagnostic Laboratory, in Reynoldsburg, detected WNV nucleic acid in the horse’s brain stem tissue