Government veterinary officials recently designated West Nile virus (WNV) as an endemic disease in the United States. The USDA’s Animal and Plant Health Inspection Service (APHIS) Veterinary Services (VS) previously had considered WNV a Foreign Animal Disease (FAD), since it had never been detected in the United States prior to 1999. (Read more about WNV at www.TheHorse.com/wnv.) The designation should help the National Veterinary Services Laboratories (NVSL) in Ames, Iowa, focus more resources on testing suspect cases of equine diseases not considered endemic in the country.

W. Ron DeHaven, DVM, deputy administrator of Veterinary Services at APHIS, made the announcement of the change to Veterinary Services’ regional directors on Nov. 20. “It is apparent that the persistence of WNV in birds and mosquitoes makes the virus difficult or impossible to eradicate,” said DeHaven in his memorandum. “It is anticipated that recurring seasonal illness in equine may occur in the United States due to WNV, Eastern equine encephalomyelitis (EEE) virus, or Western equine encephalomyelitis (WEE) virus.”

According to the memorandum, effective Dec