Although most of the focus with the West Nile Virus has been on humans, horses can also be affected. One case has been reported in Jackson County.
“People need to be aware that this virus is closer to home than they may think,” said Dr. John Thomas, a local veterinarian. “After tests from a horse in the Blair/Warren area, results came back positive for West Nile,” he said. “The horse was showing neurological problems, one of the signs of West Nile, so blood was drawn and sent to the state for further testing. The results came back positive.”
Neurological problems could include the horse staying down, or butting its head against a wall. The Oklahoma Department of Agriculture, Food and Forestry (ODAFF) reports that at least three horses have been positively diagnosed with WNV.
“The bird population is the reservoir for the virus, and it’s then spread by mosquitoes to humans and horses,” said the Assistant State Veterinarian, Dr. Michael Herrin.
He said the most likely WNV-carriers, mosquitoes, lay eggs in small pools of standing water.
“The mosquitoes then transmit the virus after they feed on birds carrying it, and within 10 to 14 days, WNV can be transmitted to horses and humans by the mosquitoes,” he said.
SYMPTOMS OF EXPOSURE Herrin said the additional signs of a WNV horse infection may also include weakness, fever, lack of coordination, seizures and blindness.
Herrin said there are several vaccines available to treat equines, and he encouraged horse owners to consult a veterinarian for development of a treatment protocol.
“Generally, a horse needs two doses of medication, about 3 to 4 weeks apart,” Hall said. “Then, like in animals who have never had WNV, they should get a dose annually.”
STOPPING WNV SPREAD
The elimination of standing water reduces the risk of WNV spreading, Herrin said.
“Horse owners should not let water stagnate in tanks or bird baths, and turn over wheelbarrows,” he said.
When possible, he said that, as for humans, outdoor exposure at dusk and dawn should be limited.
“This is when the mosquitoes that carry WNV are most active,” he said.
The number of human West Nile virus cases reported in the United States through early September is the highest year-to-date total since the mosquito-borne disease was first detected in this country in 1999, federal officials said yesterday. The number of fatalities had jumped by nearly a third from the previous week.
Texas continues to be the state hit hardest, accounting for about half of all reported U.S. cases this year. Aerial spraying of insecticide in some areas has reduced the population of mosquitoes that carry the virus. But the number of human cases is expected to rise through the month because of the lag time between infection and reporting of the illness.
As of Tuesday, a total of 1,993 cases nationwide, including 87 deaths, had been reported to the U.S. Centers for Disease Control and Prevention, a 25 percent increase in the number of cases and a 32 percent increase in deaths from the previous week.
West Nile disease can vary in severity. The onset of symptoms can take from a few days to two weeks. People 50 or older have the highest risk of severe illness.
About 80 percent of people who are infected will not develop any illness. About 20 percent will develop West Nile fever. Symptoms include fever, headache, tiredness and body aches. Occasionally, there will be a skin rash and swollen lymph glands.
The most severe type of infection causes inflammation of the brain or of the tissues surrounding the brain and spinal cord. In those cases, symptoms include headache, fever, stiff neck, muscle weakness and paralysis. There is no vaccine for humans.