Jump to: navigation, search

Equine herpesvirus 1

Equine herpesvirus 1
Virus classification
Group: Group I (dsDNA)
Family: Herpesviridae
Genus: Varicellovirus
Species: Equine herpesvirus 1 (EHV-1)

Equine herpesvirus 1 (EHV-1) is a virus of the family Herpesviridae that causes abortion, respiratory disease and occasionally neonatal mortality in horses. Initial spread of EHV-1 by a newly introduced horse through direct and indirect contact can lead to abortion and perinatal infection in up to 70 percent of a previously unexposed herd.[1] Abortion usually occurs in the last four months of gestation, two to four weeks after infection of the mare.[2] Perinatal (around the time of birth) infection can lead to pneumonia and death. Encephalitis can occur in affected animals, leading to ataxia, paralysis, and death. There is a vaccine available (ATCvet code QI05AA11), however it’s efficacy is questionable.

The virus cross-reacts with Equine herpesvirus 4 in many serological laboratory tests. Commercial diagnostic tests are available to distinguish the two viruses using monoclontal antibody based reagents. The virus is easily isolated in cell culture and can be readily detected during acute infection using molecular diagnostic methods such as polymerase chain reaction (PCR).

Recent molecular epidemiology studies have identified a single nucleotide polymorphism (SNP) which varies between EHV-1 field isolates and shows a highly statistically significant correlation with paralytic compared with non-paralytic disease outbreaks [3] . The SNP corresponds to a single amino acid change in the DNA polymerase enzyme, which is an essential enzyme for replication of viral DNA. This is a significant finding, suggesting that a point mutation in a single virus gene has a major impact upon likely disease severity during an outbreak.

In 2006, an outbreak of EHV-1 among stables in Florida resulted in the institution of various quarantine measures.[4] The outbreak was determined to have originated with several horses imported from Europe via New York, and then shipped to Florida.[5]


  1. Fenner, Frank J.; Gibbs, E. Paul J.; Murphy, Frederick A.; Rott, Rudolph; Studdert, Michael J.; White, David O. (1993). Veterinary Virology (2nd ed.). Academic Press, Inc. ISBN 0-12-253056-X. 
  2. Carter, G.R.; Flores, E.F.; Wise, D.J. (2006). "Herpesviridae". A Concise Review of Veterinary Virology. http://www.ivis.org/advances/Carter/Part2Chap11/chapter.asp?LA=1. Retrieved 2006-06-08. 
  3. Nugent J, Birch-Machin I, Smith K, Mumford J, Swann Z, Newton J, Bowden R, Allen G & Davis-Poynter N. "Analysis of Equid Herpesvirus 1 Strain Variation Reveals a Point Mutation of the DNA Polymerase Strongly Associated with Neuropathogenic versus Nonneuropathogenic Disease Outbreaks". Journal of Virology. http://jvi.asm.org/cgi/content/abstract/80/8/4047. Retrieved 2007-02-02. 
  4. "Equine Herpes Virus type1 Status Report – Florida". Florida Department of Agriculture and Consumer Services. http://www.doacs.state.fl.us/ai/Announcements/EquineVirus1StatusReport.shtml. Retrieved 2007-01-05. 
  5. "EHV-1, Outbreak Background". Florida Department of Agriculture and Consumer Services. http://www.doacs.state.fl.us/ai/ehv1/outbreak_background.shtml. Retrieved 2007-01-05. 


Premier Equine Classifieds


Subscribe to our newsletter and keep abreast of the latest news, articles and information delivered directly to your inbox.

Did You Know?

Modern horse breeds developed in response to a need for "form to function", the necessity to develop certain physical characteristics in order to perform a certain type of work... More...

The Gypsy Cob was originally bred to be a wagon horse and pulled wagons or caravans known as Vardos; a type of covered wagon that people lived in... More...

Archaeological evidence indicates that the Arabian horse bloodline dates back 4,500 years. Throughout history, Arabian horses spread around the world by both war and trade.... More...

That the term "Sporthorse" is a term used to describe a type of horse rather than any particular breed... More...