11/19/2025
A really good run-down on EHV + EHM. While most of the cases that are popping up are not local, horses get shipped from all over the country to many of these shows. So if your horses are at a boarding facility that has a lot of traffic, please ensure your horses are well vaccinated for EHV 1/4. While the vaccine does not prevent EHM, it can minimize shedding.
A good reminder to exercise caution when shipping and showing horses. Aldditionally, taking routine temperatures on your horses is an excellent idea, especially before and after attendings hows.
‼️ Recent cases of EHV-1 and EHM are confirmed after the WPRA event in Waco, Texas with potential exposure at other events. We have posted about EHV-1 and EHM in the past so here is a refresher on this highly contagious disease.
📖 What is EHV-1?
Equine Herpes Virus type-1 (EHV-1) is a virus that causes respiratory disease, abortion, neonatal death, and neurologic disease. EHV can cause Equine Herpesvirus Myeloencephalopathy (EHM), the neurologic form of herpes.
🤧How is it spread?
EHV-1 is primarily spread by direct horse-to-horse contact by respiratory secretions. However, indirect contact with contaminated equipment and personnel can spread the virus. Following infection, horses may become latent carriers and the virus may be reactivated after stress such as travel and exercise, or high doses of corticosteroids. The incubation period ranges from two to 10 days.
🩺What are the symptoms of EHV-1?
Common symptoms include fever, coughing, lethargy, nasal discharge, and inappetance. Symptoms of the neurologic form include ataxia (incoordination), weakness, difficulty standing, recumbency, loss of tail tone, and difficulty urinating.
💊 What is the treatment for EHV-1 and EHM?
Treatment is primarily supportive care. Patients with EHM may require a sling.
😷How can you protect your horse?
💉 While vaccination can decrease clinical signs and shedding, it does not protect against the neurologic strain.
👃 While at a show, avoid nose-to-nose contact with horses from other barns, and don’t share equipment such as buckets, wheelbarrows, and pitchforks. Wash your hands frequently, and take extra precautions if working with multiple groups of horses.
🌡️ Consider taking your horse's temperature twice a day when traveling. Temperatures greater than 101.5 or any signs of illness should be reported to your veterinarian immediately. And consider quarantining horses returning from horse shows or are new to the farm.
🧬How is EHV-1 diagnosed?
The virus is detected in nasal swabs and blood samples by PCR testing. At Rhinebeck Equine, we offer in-house rapid EHV-1 PCR testing on nasal swabs. Results are available in ~60 minutes.
📸: We recommend horses avoiding nose to nose contact while at horse shows and events. These Chincoteague ponies clearly didn’t hear our recommendations.