 | Dr. William Morland graduated from Kansas State University in 1970 with a doctorate in veterinary medicine. He and his wife, Dr. Laura Morland, founded the hospital in 1974. Dr. Morland is a large-animal practitioner. He also owns the Flying M Ranch. He enjoys working with his own cattle and back grounding calves. His pets other than his cattle include two Cairn terrier named Bandit and Dandy. |
Veterinary
2011-07-01 08:19:00
Equine herpes virus myeloencephalopathy
Question: What is this new disease in horses, and are my animals susceptible?
Answer: First of all, the Equine Herpes virus (EHV) is not a new disease. It is a group of viruses that are found in most horses all over the world. Almost all horses have been infected with the virus and have no serious side effects. It is unknown what causes some of the horses to develop the serious neurological forms that may be fatal. Equine herpes virus myeloencephalopathy (EHM) is another name for the neurologic disease associated with the EHV infections. The two most common strains of EHV are EHV-1, which causes abortion, respiratory disease and neurologic disease; and EHV-4, which usually causes respiratory disease only, but can occasionally cause abortion and rarely neurological disease. Respiratory disease caused by EHV is most common in weaned foals and yearlings, often in autumn and winter. Adult horses are more likely than younger ones to transmit the virus without showing signs of infection.
EHV-1 is contagious and spread by direct horse to horse contact via the respiratory tract through nasal secretions. It is important to know that this disease can also be spread indirectly through contact with physical objects contaminated with the virus:
• Human contaminated hands or
clothing
• Contaminated equipment and tack
• Contaminated trailers used for
transporting horses
• Contaminated wipe rags or other
grooming equipment
• Contaminated feed and water
buckets
The suspect and confirmed cases of EHM/EHV have been primarily from Western States. The full extent of the outbreak is unknown but under investigation. Since horses move in order to do their jobs, there is always the risk of contact between horses in the western U.S. and those from other regions of North America through contact at events or transport, however, the risk is not a problem in this area. The incidents of the disease in the horses exposed at the Western Horse Show seems to be contained and to date there has been no confirmed cases in Missouri, Kansas and Oklahoma. At this time there are only travel restrictions for horses entering Colorado and Wyoming.
Signs of the infection may appear as soon as 24 hours after exposure, but more typically it is 4-6 days. With respiratory infections there is often nasal and ocular discharge, but not a lot of coughing. There may be some enlargement of the lymph nodes. With the neurologic form there are minimal respiratory signs and a high fever may be the only warning sign.
Unfortunately, none of the current EHV-1 vaccines carry a label claim for prevention of EHM. However, it is advised that you vaccinate and booster all horses going to regular show and rodeo events.
This is one method of trying to avoid a disease outbreak but you should also take precaution when returning from an event to be sure your animals are safe. If you have further question see your local veterinarian.
