REYNOLDSBURG, Ohio—The Ohio Department of Agriculture (ODA) has confirmed the first five positive cases of West Nile Virus (WNV) for 2017 in the state. WNV is transmitted to horses by via bites from infected mosquitoes.
“We’ve had about five cases to date, and we’ll probably have some more,” said State Veterinarian Dr. Tony Forshey. “It is typical with these viral diseases that they come all at once, particularly those carried by mosquitoes. The population of mosquitoes gets high, and they are biting birds (which carry the disease), and it takes time for that to happen. That’s why we see it later in the summer and fall.”
Horse owners need to call a veterinarian and have their horses vaccinated against WNV and equine encephalitis (EEE), another disease carried by mosquitoes. The vaccines are effective, Forshey said.
“The other thing is to control against mosquito bites,” Forshey said. “We need to spray, make sure we have good insecticide spray on our horses and get rid of those mosquito breeding grounds where water is standing alone.”
ODA recommends removing stagnant water sources, keeping animals inside during the insects’ feeding times, which are typically early morning and evening, and using repellents to keep the mosquito level down.
Clinical signs for WNV can vary, Forshey said. Some horses show a bit of weakness in the hind legs, even paralysis; they may or may not have a fever but appear weak. Those symptoms can also mimic other diseases such as eastern equine encephalitis. Owners seeing these symptoms need to contact a veterinarian. Two-thirds of the horses who contract the disease survive.
These WNV cases follow the ODA’s report of EEE in an Ashtabula County horse on Aug. 24. Both illnesses were found in horses that were not vaccinated against the disease and lived near areas that are typically prone to harbor mosquitoes.
The disease is not contagious in that horses cannot give it to other horses, and people can’t give it to other people. The mosquitoes become infected, and they transmit it to people and horses.
In nearby states, Indiana has reported 10 cases of West Nile Virus while the Tennessee state veterinary laboratory has found no cases, but Tennessee Department of Agriculture veterinarians are aware of a “possible” case from another laboratory. It is considered “possible” since a horse that is vaccinated against the disease may give a false positive for the test.
Old Stone Stables in Hamilton, Ohio, has had no problem with either WNV or EEE. When owner Julie Bath accepts a new horse for boarding, they must be up to date on their shots, said barn manager Zuzana Parrette.
“We have the vets come in the spring and do vaccinations,” Parrette said. “I’ve been here for three years, and I haven’t seen an incident.”
As for Forshey, he said he will welcome the first frost, which will put an end to the disease.