USDA Takes Action On West Nile Virus

According to a USDA Animal and Plant Health Inspection Service press release from Oct. 13, the U.S. Department of Agriculture is taking several steps to ensure that the West Nile virus (WNV) does not have a detrimental effect on American agriculture. The veterinary services program of USDA's Animal and Plant Health Inspection Service is developing a diagnostic test for the virus, a surveillance program for horses, and conducting inoculation studies to determine the effects of West Nile virus on U.S. poultry and horses.

"The mission of APHIS is to protect American agriculture from foreign pests or diseases and that is what veterinary services is trying to do," said Michael V. Dunn, USDA's under secretary for marketing and regulatory programs.

Veterinary services is particularly concerned about the potential effect of WNV on horses since scientific literature indicates that horses are a susceptible species. A 1996 report from Morocco indicated 40 percent mortality in horses infected with WNV.

Preventing exposure of horses to mosquitoes is essential. No vaccine is available for WNV. Horses should be stabled inside during normal mosquito feeding times (dusk and dawn). Insect repellents are recommended.

Any horses showing clinical signs within the currently affected states of Connecticut, New Jersey, and New York, or in any other states, will be investigated by Veterinary Services (VS) as a potential foreign animal disease case. Clinical signs include anorexia, depression, or listlessness, plus any three of the following signs: fever, weakness of hind limbs, flaccid paralysis of the lower lip, impaired vision, ataxia, head pressing, aimless wandering, convulsions, inability to swallow, circling, hyperexcitability, paresis, coma, or death. Veterinary services personnel will be monitoring for West Nile virus activity along the Atlantic seaboard.

The role of domestic poultry in maintaining or transmitting WNV is not well known. According to the scientific literature, domestic poultry can develop a short-lived infection, but clinical signs are not seen. USDA's Agricultural Research Service will conduct WNV inoculation studies with turkeys, and VS' National Veterinary Service Laboratories will do the same with chickens. VS' Foreign Animal Disease Diagnostic Laboratories will do the same with equines.

About the Author

Stephanie L. Church, Editor-in-Chief

Stephanie L. Church, Editor-in-Chief, received a B.A. in Journalism and Equestrian Studies from Averett College in Danville, Virginia. A Pony Club and 4-H graduate, her background is in eventing, and she is schooling her recently retired Thoroughbred racehorse, Happy, toward a career in that discipline. She also enjoys traveling, photography, cycling, and cooking in her free time.

Stay on top of the most recent Horse Health news with FREE weekly newsletters from Learn More