A 17-year old quarter horse mare used for barrel racing was diagnosed with Equine Herpesvirus myeloencephalopathy (EHM) in Grand Junction, Mesa County, Colorado. The mare is recovering from urinary incontinence and hindlimb ataxia. The premises with a total of 10 horses is quarantined with restricted movement and all horses having temperatures taken twice daily. As of this date no further horses have shown signs of the disease.
For more information on EHM go to: https://aaep.org/sites/default/files/Documents/DiseaseFactsheetEHM.pdf
We spoke with Dr. Chelsea Luedke from Heritage Equine Clinic to get some more information on this disease. This particular strain of the Equine Herpesvirus (myeloencephalopathy (EHM)) unfortunately does not have a vaccine available currently since it is a mutation of the other forms. There has been some research saying the Rhino vaccine (meant for EHV 1/EHV 4 respiratory only) can help prevent the neurological form, but other studies have even found highly vaccinated horses at more risk. There are multiple factors; however, as horses that are typically highly vaccinated are also those at high risk due to rigorous show and travel schedules, so they are exposed to contagious diseases frequently.