REYNOLDSBURG, Ohio – A horse stabled on an Amish farm near Fredericksburg in Holmes County was euthanized earlier this month after lab tests confirmed the animal was infected with West Nile virus.
The case marks the first infected horse to be found in Ohio.
Diagnosis. The owner of the horse first noticed the animal had rear leg lameness July 19, according to state Agriculture Director Fred Dailey.
After the horse’s condition deteriorated, the owner sought veterinary help.
Blood samples were collected and submitted to the Ohio Department of Agriculture’s Animal Disease Diagnostic Laboratory, which forwarded them July 29 to the National Veterinary Services Laboratory in Ames, Iowa, for testing.
The state department of agriculture routinely assists in the testing of horses and birds as part of the state’s efforts to monitor and prevent the spread of West Nile virus.
State lab. The state Animal Disease Diagnostic Lab has received a few blood samples from other horses across the state and is expecting more from the Holmes County farm in the next few weeks.
According to state veterinarian David Glauer, the laboratory has tested around 30 equine blood samples this year.
The Holmes County sample was forwarded to Iowa for testing because the state did not have its testing procedure online at the time. Glauer said the state is now equipped and ready to handle testing.
“[The virus] is in progression in other states. As we get toward fall, we’re right in the time frame to see more samples submitted,” Glauer said.
Equine threat. More than a year ago, a blue jay was the first positive indicator that West Nile virus had officially arrived in Ohio.
In 2000, 60 cases were reported in horses from seven states, and 23 of them either died or were euthanized.
Last year, 738 horses developed clinical signs of West Nile virus infection in 20 states. Seventy-three cases were fatal, according to statistics released by the West Nile Virus Workgroup.
In 2002, infection has been confirmed in 56 horses from seven states. Seventeen of those animals were reported to have died or been euthanized.
Suspect animals. Particular attention should be paid to those animals in areas where the virus has been detected.
According to officials from Ohio State University’s department of veterinary preventive medicine, all horses that develop neurologic symptoms from August through October should be considered West Nile virus suspects.
However, not all animals that exhibit the symptoms have the virus. Many other commonly diagnosed neurologic diseases have similar symptoms, including rabies, botulism, EPM and CVM.
Symptoms. Horses are “sentinels” of the disease rather than carriers. Mosquitoes do not pick up the virus from infected horses.
Horse owners should watch for signs of infection by the virus in their animals and should consult a veterinarian if those signs are present.
Infected horses might experience loss of appetite, fever, weakness, or paralysis of hind limbs, impaired vision, loss of coordination, aimless wandering, convulsions, inability to swallow, circling, hyper-excitability, or coma.
Vaccinations. Since the disease can be fatal in horses, owners should consult with their veterinarians to consider vaccinating horses against the virus.
“Our biggest concern is the virus has been here since 1999 and we still don’t know everything,” Glauer said.
“The vaccine has been available since last year. We’ve got to be concerned with the unvaccinated animals.”
Horses must receive two doses of the killed vaccine three to six weeks apart, and full protection does not begin until at least four to six weeks after the second dose of vaccine is administered.
It is recommended horses receive vaccination before mosquito season begins.
Mild symptoms. Primarily a wild bird disease, West Nile is a mosquito-borne virus that generally causes mild symptoms that mimic the flu in humans.
West Nile virus is spread to humans by the bite of an infected mosquito. When a mosquito bites a bird that carries the virus, the mosquito becomes infected.
Once a mosquito is infected, it may transmit the virus to people or animals when it bites them.
People cannot get West Nile virus directly from another person who has the disease.
The virus can cause encephalitis, an inflammation of the brain, or meningitis, inflammation of the covering of the brain and spinal cord, in humans.
(You can contact Andrea Myers at 1-800-837-3419, ext. 22, or by e-mail at amyers@farmanddairy.com.)
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