This page looks different to our usual site because it is from our back catalogue. More recent articles are here.


EHV-1: The state by state wrap, and Canada

May 20, 2011
updated 10.42am NZT


Latest information today, not all of it official, indicates 21 confirmed cases of the neurological form of Equine Herpesvirus 1, more than 20 suspected cases, and six horses confirmed dead.

Death toll

As at 25.6.2011

New Mexico
About EHV

This report will be updated as fresh information comes to hand.

Arizona - One confirmed case in a horse who showed severe neurological disease, with reports of three suspected cases pending. Authorities are closely monitoring exposed horses. The confirmed case was at the cutting horse event in Ogden, Utah, which appears to be at the centre of the outbreak.

California - 10 cases confirmed, all linked to the cutting horse event in Ogden. The horses are in the counties of Kern, Placer, Stanislaus, Amador, and Napa. One horse has been euthanized, in Kern county. There are no reports of the disease having spread beyond horses who attended the Ogden event.

Colorado - Eight confirmed cases. Five of the horses attended the Ogden event. One did not attend but was infected through contact with one of the Ogden horses. There are 22 suspected cases. Two horses have been euthanized. One was confirmed with the disease; infection yet to be confirmed in the other. Ten quarantine and hold orders are in place in six counties - Bent, Boulder, Larimer, Mesa, Morgan, and Weld.

Idaho - 36 horses attended the Ogden event. There are 13 suspected cases, with all horses under voluntary quarantine. One horse has been confirmed positive and was euthanised with severe neurological signs. A second horse was euthanised with similar symptoms, but no testing was completed. Both attended the Ogden event.

Montana - No confirmed cases as yet, but 30-35 horses - all of whom attended the Ogden event - are under close observation.

Nebraska - Five farms have been quarantined because they house horses that went to Ogden. No cases confirmed.

Nevada - No confirmed cases.

New Mexico - One horse in the central portion of NM has died after showing severe neurological disease. The animal attended the Ogden event. A stablemate has had a fever but is otherwise normal. A horse taken to West Texas for treatment is now back home and is said to be improving. All known horses that attended the Ogden show are under quarantine.

Oklahoma - Several horses are under close observation and testing for the virus is under way. To date, no horses are confirmed positive for the disease.

Oregon - One confirmed case, in a horse that went to Ogden. Two others are showing signs consistent with the disease, but did not return a positive result in initial testing.

Texas - Twenty horses are under observation, but there are no confirmed cases to date. All 20 horses attended the Ogden event and are under movement restrictions. One confirmed case was a horse from New Mexico taken for treatment in West Texas earlier this week. The horse has since been returned to New Mexico and is now quarantined on its premises of origin. The state has not imposed any restrictions on horse movements.

Utah - No confirmed cases, but several "suspect clinical cases" have been brought to the attention of authorities.

Washington - Three confirmed cases, with tests pending on four horses showing clinical signs. All the horses were linked to Ogden. No deaths reported.

Wyoming - No confirmed cases, and no horses with clinical signs reported at this time.


Alberta - One confirmed case in southern Alberta, linked to the Ogden event.

British Columbia - Three confirmed cases.



Affiliate disclaimer