Jacob T. Goodin, DVM, DACVS
Morrie Waud Equine Clinic
Delavan, WI
Equine Herpes Virus – 1 has recently been diagnosed in Gurnee, IL. At this time all affected horses are confined to a single barn. This appears to be an isolated incident with no connection to any other outbreak in the United States.
Equine Herpes Virus-1 is a virus which affects all equids (horses, donkeys and mules). It commonly causes respiratory problems and can also cause abortion in pregnant mares. It is believed that a large percentage of horses are carriers for EHV-1, meaning they have the virus present in their body but are not showing clinical signs. A mutation of this strain of EHV-1 causes Equine Herpes Myeloencephalopathy (EHM). This is the form of the disease which causes horses to show neurologic signs. EHV-1 is spread most easily by nose to nose contact between horses, however it can easily be spread by common use of buckets, brushes, tack and caretakers.
There are no vaccines available to protect against EHM. Vaccines that target the non-neuropathogenic EHV-1 strain are available. These vaccines may help to reduce shedding of the EHV-1 virus, but have no label claims to provide protection against the neuropathogeic strain of EHV-1. Anti-viral medications have not been show to prevent the spread of the disease and thus are not recommended as a preventative to horses that have not been exposed. You and your veterinarian should decide if vaccinating your horses is warranted at this time.
The best way to prevent the spread of the neuropathogenic form of EHV-1 is the implementation and practice of good biosecurity protocols. This includes:
Isolating horses that have travelled away from their home stables for up to 14 days. This includes using separate equipment for care and feeding of these horses. Personnel interacting with these horses should changes clothes and wash hands between at risk and non at risk horses.
Monitoring rectal temperature of these horses twice daily. If a horse develops a fever (temperature of 101.5 or greater), contact your veterinarian immediately. Your veterinarian will then test for EHV-1.
If a horse at your facility is confirmed to have EHV-1, work closely with your veterinarian to treat any affected horses and prevent further spread of the virus.
We encourage everyone to contact their veterinarians and follow their recommendations regarding biosecurity and vaccination. Doing so will help to prevent further spread of EHV-1.
www.mwec.wisc.edu Office # 608-883-2995
