The Kansas Department of Agriculture issued a press release Tuesday to confirm that a horse in northeast Kansas had been euthanized after it contracted a deadly virus. According to the press release, the horse was euthanized and samples were sent to the K-State Veterinary Diagnostic Laboratory on April 25, as well as Equine Diagnostic Services in Lexington, Kentucky. The horse tested positive for EHV-1, or equine Herpesvirus.
One virus, many diseases
Dr. Elizabeth Davis, professor and section head of Equine Medicine and Surgery, said EHV-1 is a common herpes virus that can cause a number of different illnesses in horses. It can cause respiratory disease, sickness in young foals, or even for pregnant mares to abort their fetus.
This is similar to how one single virus can cause either chicken pox in human children or shingles in adults. The different diseases that come from one single virus depend on many different factors, such as age and immune system strength.
The horse in Kansas that became ill had developed neurological symptoms as the virus attacked its brain and nervous system. Neurological disease is rare for Equine Herpesvirus and often deadly. It is much more common for respiratory symptoms to appear, if any symptoms appear at all. Like herpes in humans, EHV-1 can remain dormant in horses and spread to others even if they show no symptoms of being sick.
Davis said that cases of EHV-1 causing serious illness was not as common in Kansas as it is in other states, because Kansas does not have a lot of large race tracks or events. The virus is most common when hundreds of horses are together, such as at a rodeo, and are kept in close quarters. The stress can weaken their immune system and cause carriers of the virus to “shed” to others, or can prompt a disease caused by the virus to flare up.
“In those situations, it’s usually identified quickly,” Davis said.
Horses that show symptoms of any illness are quarantined for a period of approximately 28 days, which helps control virus spread, she said.
Equine Herpesvirus is most commonly spread by nose-to-nose contact between horses. According to the press release, it can also be spread by more indirect means, such as by sharing horse trailers or even by people carrying the virus unknowingly on their clothes or hands.
The horse from northeast Kansas that contracted the virus had most recently been to Bonus Race Finals in Lincoln, Nebraska from April 10-13 and likely contracted the virus there. A horse from Wisconsin that had also been to the event was diagnosed with EHV-1, but it is unclear if that horse was the source of the illness.
Renea Bolling, manager of the Bonus Race Finals, could not confirm if any horses from K-State were present at the event. Registration is done by hometown, not college or university. So even if a student in the Manhattan area had attended, they could have registered using their parents’ home address.
Dr. Gary Anderson, director of the K-State Veterinary Diagnostic Lab, said that he could not say where exactly the infected Kansas horse was from because of privacy reasons, but he could confirm that it was not from Manhattan. Horses in the Manhattan area are in no danger from contracting the disease from the body brought to the Diagnostic Lab. However, both Anderson and Davis said that while there was no immediate danger, it is still important for horse owners to be aware of the dangers of Equine Herpesvirus and other diseases.
“We’re getting a lot of calls right now,” Davis said.
Davis recommended people contact their veterinarian if they have questions about the disease, or to discuss risk management and prevention options. They are also welcome to contact K-State Veterinary Medical Teaching Hospital’s Large Animal Desk at 785-532-5700.