The Office of the State Veterinarianannounced Delaware’s third case of West Nile Virus (WNV) found in horses this year.
The infected equine is a 10-year-old pony gelding that was purchased from a Pennsylvania livestock auction and transported to New Castle County late last month.
On August 30, the pony was observed to have a fever, was leaning and walking sideways. He progressed to show signs of wobbling and staggering, decreased tail tone, and facial nerve deficits. Samples were submitted to the National Veterinary Services Laboratory, which confirmed the diagnosis of West Nile on September 7. The vaccination history for this ponyis unknown. His condition is reported to be improving.
This is the third case of West Nile reported in Delaware horses in 2018. The first and second cases were diagnosed in August, and occurred in a 3-year-old Standardbred mare residing in Kent County with unknown vaccination status and a 2-year-old thoroughbred mare also in Kent County that was not up-to-date on its WNV vaccine. The thoroughbred horse was euthanized due to the severity of its illness.
West Nile Virus and Eastern Equine Encephalitis (EEE) are diseases transmitted to horses via the bites of mosquitoes. Humans can also be infected with WNV and EEE, but transmission requires a mosquito bite and the virus cannot be directly transmitted between horses, or between horses and people.
Two cases of WNV were confirmed in Delaware horses in 2017.
The Department of Natural Resources and Environmental Control’s (DNREC) Mosquito Control Section has seen an increase of WNV found in wild birds and sentinel chickens this year throughout the state.
The State Veterinarian urges horse owners to contact their veterinarians as soon as possible, as we are in the midst of peak mosquito season, to have horses and other equines vaccinated against West Nile and EEE.
Neither disease has a specific drug treatment, and EEE infections in horses are fatal in 70 to 90 percent of cases, and WNV in 30 percent of cases.