EHM Quarantine Released at California Barn
The quarantine has been released at a barn in San Luis Obispo County, California, where a horse tested positive for EHM in late February.
The quarantine has been released at a barn in San Luis Obispo County, California, where a horse tested positive for EHM in late February. | Wikimedia Commons

In late February, a 9-year-old Quarter Horse mare at a training barn in San Luis Obispo County, California, was euthanized after contracting equine herpesvirus myeloencephalopathy (EHM) secondary to EHV-1. The mare had recently returned from a large western discipline event in Tarrant County, Texas. Twenty-six horses on the premises were exposed and placed under quarantine.

Since then, no additional cases have been confirmed. The quarantine on the property has been released.

EDCC Health Watch is an Equine Network marketing program that utilizes information from the Equine Disease Communication Center (EDCC) to create and disseminate verified equine disease reports. The EDCC is an independent nonprofit organization that is supported by industry donations in order to provide open access to infectious disease information.

EHV 101

Herpesvirus is highly contagious among horses and can cause a variety of ailments in equids, including rhinopneumonitis (a respiratory disease usually found in young horses), abortion in broodmares, and EHM.

In many horses, the first or only sign of EHV-1 infection is fever, which can go undetected. In addition to fever, other common signs of EHV-1 infection in young horses include cough, decreased appetite, depression, and a nasal discharge. Pregnant mares typically show no signs of infection before they abort, and abortions usually occur late in gestation (around eight months) but can be earlier. Abortions can occur anywhere from two weeks to several months following infection with EHV-1.

Horses with EHM usually have a fever at the onset of the disease and might show signs of a respiratory infection. A few days later, neurologic signs such as ataxia (incoordination), weakness or paralysis of the fore- and hind limbs, urine retention and dribbling, loss of tail tone, and recumbency (inability to rise) develop.

Herpesvirus is easily spread by nose-to-nose or close contact with an infectious horse; sharing contaminated equipment including bits, buckets, and towels; or clothing, hands, or equipment of people who have recently had contact with an infectious horse. Routine biosecurity measures, including hygiene and basic cleaning and disinfection practices, should be in place at all times to help prevent disease spread.

Current EHV-1 vaccines might reduce viral shedding but are not protective against the neurologic form of the disease. Implementing routine biosecurity practices is the best way to minimize viral spread, and the best method of disease control is disease prevention.

Brought to you by Boehringer Ingelheim, The Art of the Horse

Share
Related Articles
Brown horse head of bay mare with water dripping from face, anim
Michigan Filly Tests Positive for Strangles
Portrait of a beautiful bay horse standing in a stall in the sta
2 Washington Horses Positive for Influenza
Happy Horses in Modern Stable
Strangles Confirmed in 3 Michigan Counties
Horse Stable
13 Texas Horses Positive for EIA
Newsletter
Don’t miss an important EDCC Health Alert! Get alerts delivered straight to your inbox by signing up for Horse & Rider’s newsletter.

"*" indicates required fields

Name*
Country*

Additional Offers

Additional Offers
This field is for validation purposes and should be left unchanged.