West Nile affects horses

Gretchen Cook
News Editor

   City vehicles spewing poisonous gasses, elderly in fear of a deadly plague and masses of people crowding the doctor’s waiting room, living in fear they too are marked: sounds like a scene from a Stephen King novel.

   But it’s not.

   Over the summer months the West Nile virus invaded Ohio. According to an Oct. 1 report from the Center of Disease Control Web site, the West Nile virus was first noticed in the United States in the summer of 1999.

   Last year, West Nile caused 66 human cases of severe disease and nine deaths. In 2001, Ohio first documented the virus.

   Although West Nile predominately affects the elderly according to the CDC, the modern “Bubonic Plague” captivated the nation.

   However, on a local level the biggest concern was not for human infection but for animal infection.

   There were no reported positive test results for West Nile Virus in humans living in Muskingum County according to the Ohio Department of Health.

   One crow and six blue jays within the county had West Nile.

   Veterinarian Dr. Tim Hayes, of the Animal Clinic of Cambridge, said animal-owners had paranoia over the summer that their animals had West Nile. Hayes said every sick horse was a victim of West Nile, according to their owners.

   Of domestic animals, horses are the No. 1 carrier of the virus, Hayes said. “West Nile virus is one of the fastest-growing health threats to U.S. horses today,” a publication by Fort Dodge Animal Health said. “Many experts expect the disease will soon become a threat to horses coast-to-coast.”

   According to information from the Ohio Department of Health’s Web site, of 529 horses tested by the Ohio Department of Agriculture’s Animal Disease Diagnostic Laboratory, 246 were positive for WNV. One-third of the horses died or were euthanized.

   Hayes emphasized the majority of severe WNV cases have been in northern Florida and southern Georgia.

   Nonetheless, Noble county resident and horse-owner Chris Crow worried about her horses.

   “It’s always a concern when you know it’s out there,” Crow said. “You hope and pray that they don’t get it.”

   Crow does not know of any horses who have become ill from WNV.

   Horses are actually dead-end hosts of WNV. They become ill with what is known as sleeping sickness, meaning they become lethargic, but they do not have enough of the virus in their blood to infect other animals. Symptoms for infected horses include muscle weakness, partial paralysis, fever, convulsions and coma.

   West Nile comes in several different strains. The most common strain to infect horses is encephalitis, according to Hayes. There is an Eastern, Western, St. Louis and Venezuelan strain of encephalitis. “They are all different strains but they do the same things,” Hayes said.

   According to the CDC, WNV is a flavivirus and can infect humans, birds, mosquitoes, horses and some other mammals. Encephalitis causes an inflammation of the brain.

   Over the summer vets closely monitored horses for WNV. They can be infected through birds. When a mosquito bites a bird, with the virus, it too is infected. The mosquito feeds on the horse and it becomes infected. It may take up to 15 days for the virus to become apparent in a horse.

   Scientists recently developed a vaccine to fight WNV in horses. The U.S. Department of Agriculture granted a conditional license for the vaccine.

   “This new vaccine has shown that vaccinated horses develop serum neutralizing antibodies against West Nile virus, and has been safety-tested in 649 horses of various breeds, ages and sizes,” Fort Dodge Animal Health said.

   Crow vaccinated her horses to insure their well-being. She also keeps their stalls clean and sprays them with fly spray to repel mosquitoes. Hayes and Fort Dodge Animal Health recommend keeping horses stabled during dawn and dusk, turning off lights at night, using fluorescent lights, keeping screens in stable windows, eliminating standing water, cleaning troughs and using mosquito repellent.

   West Nile season is over for now, Hayes said, because of the onset of cooler weather and the lack of mosquitoes.

   Hayes has not heard of any cases of cows, dogs, cats or small animals who have been infected with WNV. Hayes said there need not be a concern for the health of these animals and extra precautions are unnecessary.

   West Nile cannot be transmitted through drinking animal milk. Tick-borne encephalitis can be transmitted through cow or goat milk, but this is not the case with WNV, according to Dr. Lyle Petersen at a Sept. 27 CDC telebriefing.

   To King’s dismay it seems the summer’s scenario, resembling one of his murky novels, may be laid to rest and both animals and humans can live in relief.

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