Equine Herpesvirus-1 (EHV-1)

INFORMATION FROM THE HAWAII DEPARTMENT OF AGRICULTURE

ANIMAL INDUSTRY DIVISION

A multi-state outbreak of Equine Herpesvirus (EHV-1) has been traced to horses that attended the National Cutting Horse Association’s (NCHA) Western National Championships in Odgen, Utah, from April 30 to May 8, 2011.  The horses that competed in the event were almost exclusively from the Western States.  Currently, all confirmed equine cases are by “primary” exposure from direct contact at the Ogden event.

Based on the epidemiology of the disease outbreak, the Hawaii Department of Agriculture (HDOA) has increased the entry requirements for horses imported into the state effective June 1, 2011.  To view the new requirements, click on: Importing Horses.

The neurologic form, Equine Herpes Myeloencephalopathy (EHM), is occurring with this outbreak resulting in several fatal cases. Affected horses have been identified in several Western States.  A Hawai`i horse was entered in the Ogden event but, according to the owner, there are no near future plans to bring the horse to Hawaii.  Quarantines are being implemented in affected States to limit disease spread.

Equine Herpes virus is a contagious disease of equids and camelids that may spread quickly. Horse-to-horse contact, aerosol transmission, and contaminated hands, equipment, tack and feed all play a role in disease spread.  Horses infected with the neurologic form of EHV-1, may show any of the following clinical signs:  nasal discharge, lack of coordination, hind-end weakness, lethargy, urine dribbling and diminished tail tone.  A rectal temperature in excess of 102F commonly precedes other clinical signs.  Immediate separation and isolation of identified suspect cases and implementation of appropriate biosecurity measures are key elements for disease control.

USDA will be gathering information on EHV-1 cases from States and disseminating such information to Federal Area Offices and State Animal Health Officials.  We will provide this information on the HDOA website as it is received and evaluated.

Equine Herpesvirus is a reportable disease in Hawaii.

Currently, there is no equine vaccine that has a label claim for protection against the neurologic strain of this virus; however, a prudent preventative measure, in consultation with your veterinarian, may include EHV-1 vaccination. Additional information about EHV and EHM may be found at the following links:

 

Contact:

HDOA, Animal Industry Division, Livestock Disease Control Branch – Oahu:  (808) 483-7106.