Kansas Animal Health Commissioner Urges Biosecurity To Limit Spread Of Horse Virus

Kansas Animal Health Commissioner Justin Smith, DVM, said biosecurity practices will be key to stemming the spread of equine herpesvirus-1 (EHV-1), a highly contagious virus in horses that can cause respiratory issues, abortion and even neurological damage if it progresses to equine herpes myeloencephalopathy (EHM). A recent outbreak in the U.S. has been reported in at least seven states, including Texas, Oklahoma, Wyoming, Colorado, New Mexico, Pennsylvania and Arizona. There have been no reports in Kansas at this time.

EHM results from damage to the blood vessels in the brain and spinal cord. Symptoms include hind-end weakness or incoordination; difficulty standing, walking or urinating; lethargy; and fever or nasal discharge. The mortality rate due to EHM is estimated to be between 30% and 50%. If any symptoms are observed, horse owners should contact their veterinarian immediately.

“I’m told that the first sign you will see is that horses begin dragging their toes,” Smith said. “So, as they’re walking, you can see that their back feet will be dragging. As it progresses, the virus spreads to the spinal cord and will cause paralysis in some horses.”

While vaccines are available to reduce the risk of contracting EHV-1, they are not reliably protective against EHM, he said. Instead, horse owners should follow a set of biosecurity measures to protect horses. Those include: 

• Isolating horses that have been exposed to EHV-1 or are returning from events for 14 days. 
• Checking the horse’s temperature twice daily and acting quickly if a fever is detected, as that is an early symptom. 
• Keeping all horses’ EHV-1 vaccinations updated; booster shots are recommended. 
• Disinfecting water buckets, brushes, halters, bits, bridles, clothes and boots after exposure at other facilities or events.
• Minimizing contact between horses, such as avoiding nose-to-nose interactions and using barriers or extra stall space at events.
• Changing clothes and boots after returning from events and never sharing equipment between horses. 
• Checking with state animal health officials before traveling to out-of-state events. Some states have their own additional requirements, such as recent health papers. 

Kansans who suspect an outbreak of EHV-1 or EHM should notify the Kansas Department of Agriculture’s Division of Animal Health at (785) 564-6601.