Elmore County Horse Shows West Nile Virus

A horse in Elmore County has tested positive for the West Nile virus, the Idaho Department of Agriculture announced Friday, June 23. Magpies in Gem and Gooding counties also have tested positive for West Nile virus. In 2005, West Nile virus turned up in 15 of Idaho's 44 counties, infecting 13 humans, 114 horses, 15 birds, and one dog. Since the introduction of equine vaccines, the number of horses reported with West Nile infections has decreased dramatically nationwide, from 15,000 horses in 2002 to 1,341 in 2004 and 1,100 in 2005 according to the USDA. "Almost all of the 113 Idaho horses diagnosed with West Nile virus last year were not vaccinated. Our advice to horse owners is to make sure that their horses are protected, and if not, they should contact their veterinarian immediately," said Marilyn Simunich, a veterinarian at the Idaho State Department of Agriculture. The most common sign of West Nile virus in horses is weakness, usually in the hindquarters. Weakness may be indicated by a widened stance, stumbling, leaning to one side and toe dragging. In extreme cases, paralysis may follow. Fever is sometimes evident, as are depression and fearfulness. Lip smacking, chewing movements and fine muscle tremors may be noticed. Humans cannot contract West Nile virus through contact with an infected horse. The recent Elmore County case serves as a reminder of the importance to vaccinate horses against the virus and for people to take appropriate steps to protect themselves against mosquito bites. In Idaho, the appearance of equine cases has preceded cases in humans by three to four weeks. West Nile virus is spread by mosquitoes. The virus was first discovered in 1999 in New York. Since then, it has spread westward and now is found in all 48 continental states. The virus showed up in Idaho at a commercial fish farm in the Hagerman valley in November 2003. One worker at the farm tested positive, making him the first person to acquire West Nile virus in Idaho. People and animals are generally infected through the bite of a mosquito. The human cases in Idaho last year all were reported in August and September in southwestern Idaho - two each in Ada, Canyon, Elmore and Gooding counties; and one each in Owhyee, Twin Falls and Washington counties. The 13 cases included 10 cases of West Nile fever and three cases of the more serious West Nile encephalitis or meningitis. No fatalities were reported. The best protection is to avoid mosquito bites. Simple tips for prevention include: ¥ Cover up exposed skin when outdoors. ¥ Apply insect repellent containing DEET and approved by the EPA to exposed skin and clothing. Follow instructions on the product label, especially for children under 12. ¥ Avoid outdoor activities at dawn and dusk when mosquitoes are most active. ¥ Eliminate standing water that may provide mosquitoes a place to breed. ¥ Empty birdbaths and clean decorative ponds every 3 to 6 days. ¥ Repair or install screens on doors and windows. ¥ If you have a horse, vaccinate it; one-third of horses infected by West Nile virus die. ¥ Hunters should wear latex gloves when field dressing and handling wild game. ¥ Cook meat thoroughly. ¥ Report dead birds to your local Fish and Game office. The Department of Agriculture's Urban Pest Management program also has information on steps residents can take to prevent home-grown mosquito infestations. For information visit the Ag Department's Website at: http://www.idahoag.us or the Fish and Game Website at: http://fishandgame.idaho.gov.