Horses exposed to EHV-1 at Utah show

Horses from at least 29 states and Canada may have been exposed to equine herpes virus-1 or EHV-1 at the recent National Cutting Horse Association Western National Championships in Ogden, Utah held April 29th through May 8th. The infection came to light after two horses in Colorado became ill after returning from the show. A horse in Washington State that was at the show also tested positive for the virus.

Wisconsin State Veterinarian Dr. Bob Ehlenfeldt is urging those who had horses at the show to isolate them from other horses for at least 21 days. EHV-1 spreads when horses in close contact cough or sneeze, and on contaminated hands, water and feed. “If a horse gets infected with EHV-1, there’s nothing anyone can do except try to make the horse more comfortable. The infection may run its course, or it may kill the animal. There’s no treatment, and no vaccine for the worst strain that attacks the central nervous system,” says Ehlenfeldt. It may also affect the respiratory and reproductive system. There is no threat to human health.

The NCHA is closely monitoring the developing situation and cautioning against the interstate transport of infected horses:

In an effort to be proactive and provide the maximum safety to horses across the country, affiliate organizations and show producers in Montana, Oregon, Oklahoma, Texas, California, Wyoming, New Mexico, Washington and Nevada have cancelled previously scheduled shows for the weekend of May 20 – 22, 2011. The NCHA supports these decisions to cancel shows that were made in the best interest of horse health. While the NCHA is at present not mandating cancellation of all shows nationwide scheduled for the weekend of May 20 – 22, we do strongly urge all show producer to consider the possible horse health risks of conducting an event this weekend.

More information and updates are available at the NCHA website.

Dr. Ehlenfeldt recommends these biosecurity precautions to prevent introducing and/or spreading the disease:

• Isolate for seven days new horses and those returning from shows or anyplace where they’ve mingled with other horses. If they were exposed to confirmed EHV-1 infections, isolate them at least 21 days after returning.
• Encourage barn personnel and riders to wear leather or rubber footwear that can be disinfected, and keep a disinfectant tub with a 1:10 bleach-water solution at the barn entrance. Ask all visitors, including blacksmiths and veterinarians, to step in the disinfectant wash before entering the barn, and change the solution daily.
• Wash hands before handling horses.
• Don’t share water buckets, feed tubs or stalls among horses.
• Segregate horses into the smallest possible groups to limit the number of animals exposed if one is infected.
• Take rectal temperatures daily. Isolate any horse that has a temperature over 101 degrees F. or any other sign of illness, and call a veterinarian.

USDA APHIS chart on states where horses affected by EHV01