Encephalomyelitis is defined as inflammation of the brain and spinal cord. Both these conditions often share the same causative agent and produce a similar clinical picture. The two words are often used interchangeably.
Viruses are the most common cause of equine encephalitis.
The following is a list of infectious agents which can cause encephalitis in horses. They are usually limited to specific world distributions. C lick here to see the World Distribution of West Nile virus.