EHV-1 Outbreaks

More EHV-1 infected horses in California, Tennessee, Utah and Illinois add to the tally in the United States and Canada.

The American Quarter Horse Journal
March 8, 2013

AQHA Ranching photo

To learn more about EHV-1 and EHM, visit the AQHA EHV-1 Information page. (Journal photo)


From TheHorse.com (March 7, 2013)

Diagnostic tests done at the University of California, Davis, have confirmed that a euthanized horse stabled at Santa Anita Park, in Arcadia, California, was positive for equine herpesvirus type-1.

On March 5, My Sugar Sugar, an unraced 3-year-old Thoroughbred filly trained by Eddie Truman, required euthanasia after developing neurologic signs. There have been no other reported cases of EHV-1 at Santa Anita.

According to a statement from the California Horse Racing Board, My Sugar Sugar had been feverish four days earlier and developed neurologic signs on day four. Biosecurity procedures were implemented that day and the California Department of Agriculture was notified of a suspected case of EHV-1.

The average incubation period for EHV-1 is four to seven days, with the majority of cases being three to eight days, but with some taking up to 14 days. All horses in the stable are being closely monitored and none of the others has exhibited signs of fever or illness.

Read the rest of this article from TheHorse.com.


From TheHorse.com (March 7, 2013)

One horse in Shelby County, Tennessee, has tested positive for the neurologic form of equine herpesvirus type-1, according to a March 6 statement from the Tennessee Department of Agriculture. Shelby County is located in the southwestern part of the state.

"The case involves one premises which has been quarantined," the statement read. "The affected horse has been isolated and is under the care and observation of a veterinarian. Strict biosecurity measures have been implemented to prevent any further exposure."

While an investigation into the source of the disease is under way, officials indicate "there appears to be no known connection to the current EHV-1 outbreak in Florida, and state animal health officials have no reason to believe that other horses have been exposed at this time."

Continue reading this article from TheHorse.com.


From the Illinois Bureau of Animal Health and Welfare (March 6, 2013)

The Illinois Bureau of Animal Health and Welfare has received laboratory confirmation of an EHV-1 infection in a private boarding stable in Lake County in Illinois. Several horses in the stable are currently exhibiting neurologic signs consistent with those exhibited in EHV-1 infected horses. The horses stabled in the facility have been placed under quarantine by the Bureau of Animal Health and Welfare. This quarantine will remain in place until such time as it is determined that exposure to these horses no longer poses a risk to other horses.

At the present time, no link has been established between these affected horses and any organized equine


From the Utah Department of Agriculture and Food (March 5, 2013)

The Utah state veterinarian has confirmed seven cases of EHV-1 in Utah, all of which are confined to locations in Cache County. The state veterinarian's office is restricting the movement of the infected animals as a precaution to prevent the spread of the disease. The outbreak remains confined to Cache County, as there have been no other reports of EHV-1 symptoms in horses in other areas of the state. Nonetheless, horse owners throughout Utah are advised to take extra biosecurity precautions when taking their animals to shows or public arenas.

Two of the horses have been humanely euthanized because of their condition. The remaining animals are being treated, and are under veterinary care. The Cache County Fairgrounds Horse Arena has closed its riding arena until further notice because all of the horses had been at the facility recently. Horse owners who have taken their animals to the Cache County Fairgrounds Arena during the past 30 days should monitor their horse's temperature and report concerns to their local veterinarian.

The state veterinarian recommends that horse facilities proceed with planned equine events, and that horse owners planning on traveling to an event should take their horse's temperature daily, beginning three days prior to travel and daily during the event. Horses with temperatures of 103 and above should not travel or mingle with other horses. Horses should be isolated for two weeks after returning home from an event, during which time they should be monitored for disease symptoms.

Continue reading the statement from the Utah Department of Agriculture and Food


From the Florida Department of Agriculture and Consumer Services (February 27, 2013)

The Florida Department of Agriculture and Consumer Services announced seven positive cases of EHV-1 confirmed in horses in Florida. Six of the confirmed cases are linked to the Horse Shows in the Sun event in Ocala. The department issued a quarantine order to the entire venue hosting the HITS event and other areas where exposed horses have traveled.

Continue reading the Florida Department of Agriculture’s status on the Florida EHV-1 outbreak.


From www.thehorse.com (February 28, 2013)

One mare is dead and two horses are showing neurologic signs in an outbreak of the neurologic form of EHV-1 in Quebec that has left more than 50 horses in quarantine.

A 12-year-old Quarter Horse mare showed signs of illness last week, including fever, lethargy, and difficulty standing and walking, according to treating veterinarian Dr. Isabelle Morin of the Clinique Vétérinaire Sagamie in Alma, Quebec. The horse then "rapidly deteriorated" over the next 24 hours and was unable to stand. She was humanely euthanized.

Necropsy results confirmed the presence of neurologic EHV-1, Morin said. All 53 remaining horses at the Bédard Quarter Horse riding stable in Chicoutimi, Quebec, were immediately placed in quarantine by their veterinarians and their owner.

Read the rest of this story from www.thehorse.com.

New Jersey

From the New Jersey Department of Agriculture (February 22, 2013)

The New Jersey Department of Agriculture quarantined two farms – one in Franklinville, Gloucester County, and one in Dennisville, Cape May County – after horses at each farm were exposed to a horse that developed the highly infectious equine herpes myeloencephalopathy.

Testing confirmed the horse developed EHM caused by EHV-1. The horse became recumbent and was humanely euthanized on February 15.

Read the rest of the New Jersey Department of Agriculture’s status on the state’s EHV-1 outbreak.

EHV-1 Preparedness

Please use these resources regarding EHV-1, EHM and biosecurity, brought to you by The American Quarter Horse Journal:

  • Travel Safely: Good biosecurity both at home and on the road will help keep your horses healthy.
  • The Facts on EHV-1: Recognize the signs of equine herpesvirus-1 and learn how to protect your horse from the risks of the virus.
  • Strike a Balance With EHV-1: Learn how to strike a balance between showing and protecting your herd against equine herpesvirus-1 myeloencephalopathy with tips from Dr. Tom Lenz.
  • EHV-1 Testing: AQHA Professional Horseman Al Dunning weighs in on his experience with EHV-1 testing, and Dr. Tom Lenz suggests alternatives to testing.

To learn more about EHV-1 and EHM, visit the AQHA EHV-1 Information page.