DES MOINES, Iowa - The Iowa Department of Agriculture and Land Stewardship today announced that a horse stable in Warren County has had several confirmed cases of Equine Herpesvirus Myeloencephalopathy (EHM). EHM is the neurological disease associated with Equine Herpesvirus (EHV). There is no human health threat from the disease.

All horses at the facility are being monitored for the disease and are not permitted to leave the site.

EHV is spread by direct horse-to-horse contact or through contact with objects contaminated with the virus. This can include tack, grooming equipment and feed and water buckets. Signs of the disease include fever, decreased coordination, and failure to maintain balance, lethargy and inability to rise.

EHV is a reportable disease in Iowa. If a horse owner has questions about the disease they are encouraged to contact their local veterinarian. More information about the disease is available here from the USDA Animal and Plant Health Inspection Service (APHIS) .

- Iowa Department of Agriculture

Equine Herpes Virus (EHV-1) is a contagious equine virus that is most commonly known to cause abortion and can also cause respiratory disease, as well as neurologic disease. The neurological form also known as Equine Herpes Virus Myeloencephalopathy (EHM) involves the brain stem and results in nervous system dysfunction such as acute paralytic syndrome where horses are weak and incoordinated, stumbles, dribbles, and can't stand. The disease can progress to full recumbency where horses are often humanely euthanized.

The virus is spread through contact with facial secretions that contain the virus such as snot and saliva. This includes being near a horse that is coughing or sneezing, direct horse-to-horse contact, contact with contaminated feed, equipment, tack, and people's hands and clothing. Once a horse is infected it can become a carrier of the virus. During times of stress, the virus can emerge and the horse may begin shedding the virus.
The incubation period is variable ranging from 24 hours to 2 weeks. The first symptom seen is a fever with other signs ensuing in the following days including abortion, respiratory disease, or neurological signs. Shedding by the respiratory route typically lasts for 7-10 days and veterinarians recommend quarantine for a period of 14 to 28 days after resolution of clinical signs to be sure.

If a horse contracts the neurologic form, treatment is directed at supportive care. Horses will be managed according to their individual signs. It is recommended that horses who will be coming in contact with other horses during the year receive at least one dose of EHV-1 and EHV-4 vaccine two weeks prior to travel.

Owners should practice biosecurity measures including not sharing tack; cleaning and disinfecting your horse trailer after transporting horses other than your own with a 1:10 bleach:water solution; provide appropriate food, water and shelter to minimize stress on your horses; quarantine and monitor temperature of new horses for at least 14 days before introducing them to your existing herd, and if your horse exhibits any neurologic signs, contact your veterinarian immediately. A good site to calculate the biosecurity on your farm is http://www.equineguelph.ca/Tools/biosecurity_2011.php 

Additional Resources

• Center for Food Security and Public Health http://www.cfsph.iastate.edu/?lang=en 
• Equine Herpesvirus (EHV) Myeloencephalopathy-A Guide To Understanding the Neurologic Form of EHV Infection http://www.aphis.usda.gov/vs/nahss/equine/ehv/equine_herpesvirus_brochure_2009.pdf 
• AAEP http://www.aaep.org/pdfs/control_guidelines/Equine%20Herpes%20Virus.pdf 
• Gluck Equine Research Center http://www2.ca.uky.edu/gluck/BiblioEHV1.asp 
• EHV-1 (Enough Herpes Virus - for 1) by Dr. Ramey
   

On April 28, 2015, Senators Mike Enzi (R-WY) and  Michael Bennet (D-CO) introduced the Senate version of the National Forest Service Trail Stewardship Act of 2015 (S.1110).  The bill would direct the Forest Service to take several actions to help address the current trail maintenance backlog that is adversely impacting all trail users on many national forests, including equestrians. Earlier this year, Congresswomen Cynthia Lummis (R-WY) and Tim Walz (D-MN) introduced the House version of the bill (H.R.845). Continue Reading