## Overview Equine herpesvirus-1 myeloencephalopathy (EHM) is the neurologic form of equine herpesvirus-1 infection. Neuropathogenic strains cause vasculitis and ischemic damage to the spinal cord. Typical signs are fever followed by acute hind-limb ataxia, urinary incontinence, and potentially rapid progression to recumbency. Outbreaks occur. ## Causes Neuropathogenic equine herpesvirus-1 (often associated with a specific DNA polymerase mutation). ## Diagnosis Clinical signs plus polymerase chain reaction testing of nasal swabs and blood, and cerebrospinal fluid analysis. ## Treatment Supportive care, anti-inflammatories, and nursing for recumbent horses. Antiviral drugs are sometimes used. Isolation is critical to prevent spread. ## Recovery and Prognosis Guarded. Horses that remain standing have a better chance. Recumbent horses have high mortality. ## Prevention Vaccination reduces respiratory disease and abortion but does not fully prevent neurologic disease. Biosecurity during outbreaks is essential.
fever followed by acute hind-limb ataxia and weakness; urinary incontinence; perineal hypalgesia; may progress to recumbency
## Overview Equine herpesvirus-1 myeloencephalopathy (EHM) is the neurologic form of equine herpesvirus-1 infection. Neuropathogenic strains cause vasculitis and ischemic damage to the spinal cord. Typical signs are fever followed by acute hind-limb ataxia, urinary incontinence, and potentially rapid progression to recumbency. Outbreaks occur. ## Causes Neuropathogenic equine herpesvirus-1 (often associated with a specific DNA polymerase mutation). ## Diagnosis Clinical signs plus polymerase chain reaction testing of nasal swabs and blood, and cerebrospinal fluid analysis. ## Treatment Supportive care, anti-inflammatories, and nursing for recumbent horses. Antiviral drugs are sometimes used. Isolation is critical to prevent spread. ## Recovery and Prognosis Guarded. Horses that remain standing have a better chance. Recumbent horses have high mortality. ## Prevention Vaccination reduces respiratory disease and abortion but does not fully prevent neurologic disease. Biosecurity during outbreaks is essential.
fever followed by acute hind-limb ataxia and weakness; urinary incontinence; perineal hypalgesia; may progress to recumbency