Horse owners urged to watch for symptoms of West Nile virus

BISMARCK – North Dakota's top animal health official is urging horse owners to have their animals vaccinated against West Nile virus (WNV) and to contact their veterinarian if their horses show symptoms of WNV.

“It is very important to call your veterinarian immediately to collect samples for diagnostic testing," said Dr. Susan Keller, the state veterinarian. “The symptoms of WNV infection may be similar to those of rabies.”

Symptoms of the disease may include loss of appetite, head tremors, muscle twitches or inability to stand. Any unusual changes in a horse's behavior should be reported to a veterinarian.

Keller said North Dakota is experiencing a number of equine WNV cases, some fatal.

“Proper vaccination is the key to controlling the disease,” Keller said. “The initial vaccination consists of two shots within three to six weeks of each other. An annual booster is also necessary to maintain immunity. Owners should talk with their veterinarians for the best protocol.”

She also said that horse and stable owners should also take measures to reduce mosquito populations near their premises.

“Draining or treating stagnant water, mowing grass and weeds, applying repellents and putting up screens can protect your home or stable from mosquitoes,” she said,

WNV causes a form of encephalitis, an inflammation of the brain. Birds serve as a host for the virus, which is then spread by mosquitoes to other birds and animals, including horses and humans. The principal vector is the Culex mosquito which prefers dry conditions, such as North Dakota is experiencing. Horses cannot spread the disease.

North Dakota recorded its first case of WNV in horses in 2002.