WASHINGTON, D.C. – A new vaccine to help local horse owners with the prevention of West Nile virus is now available.

The United States Department of Agriculture announced that it has issued a conditional license to Fort Dodge Laboratories, Inc., of Fort Dodge, Iowa, for the vaccine. USDA’s Animal and Plant Health Inspection Service issues conditional licenses for veterinary biologics products to meet an emergency situation, limited market, local situation, or special circumstance.

The special circumstance addressed here is the need for a product to aid in the prevention of disease caused by West Nile virus.

West Nile virus is a mosquito-borne virus that was first detected in the United States in 1999. The virus, which can cause encephalitis, or inflammation of the brain in animals and in some cases, humans, has been found in Africa, western Asia, the Middle East, the Mediterranean region of Europe, and most recently in various parts of the eastern United States.

West Nile virus infection in horses may include both central nervous system and peripheral nervous system signs. Although horses can be infected by the virus, there is no documentation that infected horses can spread the virus to uninfected horses or other animals. In 1999 and 2000, 85 horses were infected with the virus, and 32 of these cases resulted in death.

The most common signs of West Nile virus infection in U.S. horses have been stumbling or un-coordination, weakness of limbs, partial paralysis, muscle twitching and death. Fever has been detected in less than one-quarter of all confirmed cases.

Horse owners planning to ship their animals to other countries should be aware that vaccinated animals may not meet the import requirements of those countries due to the presence of certain antibodies in their blood. While the presence of this antibody is not permanent, it could lead to complications in shipping the horse.

For more information regarding this vaccine, contact Fort Dodge Animal Health’s Professional Services department at 1-800-533-8536.