Office of the Ohio State Veterinarian
The Office of the Ohio State Veterinarian has reported five confirmed cases of equine West Nile virus. A 4-year-old Thoroughbred gelding from Cuyahoga County showed an onset of clinical signs on October 7th, 2018 when the 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. The veterinarian suspected a high fracture, but the radiograph was negative. Symptoms progressed to a head tilt, muscle fasciculations in the neck and shoulders and then then horse went down. The horse was humanely euthanized and brought to the Ohio Department of Agriculture for a necropsy. After determining that brain tissue was negative for rabies, PCR assay at the Ohio ADDL detected West Nile Virus (WNV) nucleic acid in brain stem tissue of this horse. A 7-year-old Quarter Horse gelding from Licking County had an onset of clinical signs on 10/04/2018 when the owner noticed that the horse was dragging his left leg, lethargic, and had weakness in the rear legs. The days prior the horse had a lack of appetite. The veterinarian responded and found the horse down and treated the horse. A serum sample was collected and submitted to NVSL, they reported an IgM capture ELISA titer of 1:400 or greater, suggesting recent exposure to West Nile Virus. The horse is alive and recovering as of 10/06/2018. A 10-year-old Paint gelding from Holmes County showed onset on 10/17/2018 when the attending veterinarian received a call for a down horse. Upon arrival the horse was laterally recumbent, couldn't rise and had a temperature of 100.8°F. A serum sample was collected and submitted to NVSL, they reported an IgM capture ELISA titer of 1:400 or greater, suggesting recent exposure to West Nile Virus. The horse died spontaneously that night. A 7-year-old Percheron mare from Holmes County showed an onset of clinical signs on 9/11/2018. The veterinarian received a call for a down horse that was agitated; the veterinarian treated the horse, but it died spontaneously that night. A serum sample was collected and submitted to IDEXX, they reported a positive IgM capture ELISA, suggesting recent exposure to West Nile Virus. A 16-year-old Paint gelding from Carroll County showed an onset of clinical signs when the owner found the horse down in the pasture in the afternoon on 10/19/2018, it struggled to rise. The veterinarian responded, and the horse was down with a fever of 100°F, HR 65, RR36 (irregular), full body muscle fasciculations, and had hyperesthesia. The veterinarian treated and collected a serum sample. The veterinarian was called back out the next day because the horse was down. A serum sample was collected and submitted to Cornell, which reported an IgM capture ELISA of 6.79 (>3.3 = Positive), suggesting recent exposure to West Nile Virus. The horse was euthanized on 10/20/18. None of the horses were vaccinated against WNV. This brings the total number of confirmed equine WNV cases in Ohio to 48.