A review of equid herpesvirus 1 for the veterinary practitioner. Part B: pathogenesis and epidemiology.

Equid herpesvirus (EHV) type 1 is a common pathogen of horses with worldwide distribution. Infection with EHV-1 can be subclinical, or can result in sociologically and economically important outcomes such as abortion, neonatal death or neurological disease. The perceived recent increase in the reported cases of EHV-1 neurological disease in the United States of America and Europe over the past decade has caused concerns amongst veterinarians and horse owners worldwide. This review provides an update on the recent developments in our understanding of the pathogenesis and epidemiology of EHV-1 and associated diseases, with an emphasis on epidemiological data from Australasia. Many aspects of the pathogenesis and epidemiology of equine herpesvirus myeloencephalopathy still remain to be elucidated. This is an active area of current research worldwide.