Horse owners should practice good biosecurity if they take their animals where they will come in contact with other horses, such as horse shows, to protect them against the equine herpes virus, North Dakota State University animal experts say.

At least 44 horses in nine Western states have tested positive for the virus, known as EHV-1.

The U.S. Department of Agriculture’s Animal and Plant Health Inspection Service reports that 308 horses from 18 Western states were exposed to the virus at the National Cutting Horse Association’s Western National Championships in Ogden, Utah, between April 30 and May 8. About another 700 horses are at risk of contracting the virus through secondary exposure.

“If you go to shows, have your horses current on all vaccinations, have current health papers, and take all your own tack and equipment,” says NDSU Extension Service veterinarian Charlie Stoltenow. “Do not share equipment with others or ask to use theirs.”

Stoltenow and NDSU Extension equine specialist Carrie Hammer also recommend that anyone with a horse that was at an event where EHV-1 has been confirmed should keep that horse away from other horses for 28 days.

EHV-1 is a contagious viral equine disease that can cause respiratory or neurologic infection, abortion in mares and even death. It can be spread by airborne pathogens as well as through feed, clothing, boots and hands. Humans cannot contract the virus, but they can be a carrier. The virus is found worldwide.

“There is no known cure for an EHV-1 neurological infection, except for nursing care,” Stoltenow says. “That’s why it is important to contact your veterinarian immediately in case you suspect an infection in your horse. The veterinarian can make the diagnosis and prescribe the best supportive therapy for your horse.”

No vaccines are available specifically for the neurological effects of EHV-1.

Neurological symptoms include staggering, stumbling, head tilting or behavior changes. Rabies or West Nile virus may have the same symptoms, so contacting a veterinarian quickly is important for getting the right diagnosis and treatment, according to Stoltenow.

“A high temperature is often the very first sign, so taking daily temperatures of at-risk horses can be beneficial in detecting the disease early,” Hammer says.

The virus rarely causes neurological signs, but when it does, those symptoms can be very severe, Stoltenow adds.

Some North Dakota horses were at the Utah competition. However, they are stabled in Minnesota, Hammer says.

NDSU Agriculture Communication - May 26, 2011