According to the American Association of Equine Practitioners (AAEP), EHV-1 can cause respiratory disease, neurologic disease and abortion in pregnant mares.
Symptoms of respiratory infection may include fever, coughing and nasal discharge. Fever is typically the first sign of infection and is sometimes the only symptom. It is often undetected by owners and caretakers. Commonly called Rhino, most horses are vaccinated against this strain.
Symptoms of neurologic disease from EHV-1 include lack of coordination in the hind limbs, recumbency (frequent or constant lying down) and partial loss of bladder control. These symptoms sometimes follow respiratory symptoms. The neurologic strain of the disease is of highest concern as it has the potential to be fatal and there is no reliable vaccine to protect against it.
Most horse owners do not need to worry at this time as risk of infection is low. However, if your horse or other horses at his barn attended the NCHA Western National Championships, you should take your horse’s temperature regularly and tell your vet if he has a fever. Your vet will be able to test for EHV-1 and can give you anti-viral drugs if your horse is infected. Take extra biosecurity measures if your barn is at risk.
While the disease is harmless to humans, it is highly contagious between horses. It spreads via nose-to-nose contact between horses or inhalation of droplets from an infected horse snorting or coughing. The virus can also be transmitted indirectly on stall walls or clothing. For this reason, it is important for anyone in an at-risk area to change or thoroughly clean their clothes–including riding gloves, helmets and boots—when visiting different barns.
As a precaution, several upcoming NCHA competitions in the at-risk area have been canceled. Additionally, Colorado State University has temporarily closed its veterinary teaching hospital to nonemergency cases.
The NCHA is keeping up-to-date information on its website.
Get more information on the AAEP’s fact sheet.
Read more from the USDA.