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University of Tennessee Veterinary Medical Center Reminds Horse Owners to Vaccinate against West Nile Virus

(Knoxville, TN. August 29, 2012)-- West Nile Virus (WNV) in horses is sometimes fatal, but equine clinicians at the University of Tennessee Veterinary Medical Center say it is not too late to administer a vaccine that is highly effective in protecting horses. The Tennessee Department of Agriculture confirmed its first case of WNV infection in a Tennessee horse this year. 

Infected mosquitoes spread West Nile Virus which was first detected in the United States in 1999. The virus causes encephalomyelitis, or inflammation of the brain and spinal cord. Mosquitoes acquire the virus from birds and pass it on to other birds, animals, and people.  Last year, there were three equine cases in Tennessee.

(Dr. Carla Sommardahl discusses West Nile Virus in this video.)

Symptoms of WNV in horses may include weakness in the limbs, stumbling and incoordination, loss of appetite, fever, depression, lethargy, and muscle twitching. A blood test is used to confirm the diagnosis of the disease. Treatment includes providing supportive care and medication to treat the inflammation. WNV can be fatal to older horses or those with weakened immune systems. Contact a veterinarian if your horse shows any of these symptoms. Several other diseases cause the same symptoms. 

Dr. Carla Sommardahl, clinical associate professor at the UT College of Veterinary Medicine, says owners should keep horses vaccinations up-to-date. "There are several West Nile Virus specific vaccines available that are very effective against this virus," says Sommardahl. "We recommend vaccinating your horse in the spring and fall, because the mosquito season lasts so long in our area."  Even if you have not vaccinated your horse, it is never too late. There is a vaccination available that does not require a booster shot and would provide some protection against the virus.

In addition to vaccination, preventing animals' exposure to mosquitoes is essential. Remove sources of standing water in which mosquitoes can breed. Mosquitoes can breed in any puddle that lasts more than 4 days. Clean water troughs on a regular basis.  Avoid outdoor activity at dawn and dusk. If possible, maintain a circulating air-flow through horse barns. The American Association of Equine Practitioners offers additional information about reducing the risk of WNV infection.

As of August 29, eight human cases have been reported in the state this year. Sommardahl reminds people they cannot contract the illness from their horse. "West Nile Virus is not transmitted from horse to horse, horse to human or human to horse. It is transmitted through a bite from an infected mosquito."

Click here for information regarding West Nile Virus in llamas and alpacas.

For more information about WNV surveillance, visit the United States Department of Agriculture or the Centers for Disease Control and Prevention.



Posted: 08-29-12 Viewed: 34514 times

Media Relations

Sandra Harbison
College of Veterinary Medicine
University of Tennessee
2407 River Drive
Knoxville, TN 37996

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