Update: 7 Horses Now Dead in EHV Outbreak in western USA, Canada

10 years ago StraightArrow Comments Off on Update: 7 Horses Now Dead in EHV Outbreak in western USA, Canada
Health officials inspecting horses during the 2006 equine herpes virus outbreak in South Florida. © Ken Braddick/dressage-news.com


Seven horses have died or been euthanized in the outbreak of the highly contagious equine herpes virus with 33 confirmed and 53 suspected cases of the virus in a vast area of the western United States and Canada, according to a report prepared by the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service released Friday.

The first official national compilation (for complete report click on ehv_sitrep_051911) from the current outbreak among horses that were at the National Cutting Horse Western Championships in Ogden, Utah, early this month, reported EHV-1/EHM  confirmed and suspected cases or deaths in Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oklahoma, Oregon, Texas, Utah, Washington and Wyoming. Separately, the Canadian provinces of British Columbia and Alberta reported another four cases. No other horses in other disciplines are reported to have been affected.

Several horse shows–including at least one sanctioned dressage show in Las Vegas–and clinics have been cancelled or postponed throughout western states, including clinics for jumpers and reining in Colorado. Three Oregon Dressage Society events were postponed and a fourth was moved.

Las Vegas Dressage Spring Fling III scheduled for Saturday and Sunday with about 30 horses entered was canceled, organizer Susan Gilligan said, because of the outbreak. Organizers of a one-day recognized competition in Kirkland, Washington, announced cancellation of the competition because of the EHV outbreak.

However, two competitions in California, a CDI1* at Woodside and a California Dressage Society show at San Juan Capistrano, were planning to proceed after reviewing antiviral-meds-info.com from the state Department of Food and Agriculture.

Colorado and Wyoming have imposed restrictions on horses entering the state, but other states with horses affected by EHV have not.

An outbreak of the equine herpes virus in South Florida in December, 2006, just weeks before the start of the winter dressage, hunter-jumper, polo and Thoroughbred racing circuits led to the deaths of six horses.

Due to the huge area directly impacted by the latest outbreak–the eight states where confirmed or suspected cases have occurred is almost one-third the total land mass of continental United States–the U.S. Department of Agriculture agreed to a request by the American Horse Council and American Association of Equine Practitioners to coordinate information gathering and distribution among states.

The national report stated that horses died or were euthanized in Arizona (1), California (1), Colorado (2), Idaho (2) and New Mexico 1.

In addition to the deaths, cases of EHV-1 or EHM by state: California (10 confirmed), Colorado (9 confirmed, 19 suspected); Idaho (1 confirmed, 16 suspected), Montana (1 suspected), Nevada (3 suspected), New Mexico (2 confirmed, 4 suspected), Oklahoma (1 suspected), Oregon (2 confirmed), Texas (1 confirmed, 1 suspected), Utah (5 confirmed, 3 suspected), Washington (3 confirmed, 4 suspected) and Wyoming (1 suspected).

Equine Canada reported three cases in British Columbia and one in Alberta.

Biosecurity measures recommended for horses who attended the Odgen event or may have come in contact with horses affected include:

-Isolate exposed horse a minimum of 30 feet away from all other horses (round pen if necessary) for 21 days;
-Monitor temperature twice a day for 14 days;
-Immediately report temperatures over 102F (39C) to your private veterinarian;
-Use separate equipment, bucket, halters/leads for isolated horse;
-Wear protective clothing when handling isolated horse–coveralls, boot covers, gloves. Do not use same clothing with other horses;
– Ideally, use separate personnel for isolated horses, and
-Restrict movement.

Key to limiting the disease from spreading is Isolation of sick horses. Sick horses are shedding virus and should be removed from exposing additional horses.

Symptoms can include fever, sneezing, slobbering and other mild symptoms. Serious cases of the disease are rare, but can include staggering, hind-end paralysis and even death of the horse.

The virus can usually survive for about a week on surfaces, though under the optimum conditions could last as long as 30 days.

The American Association of Equine Practitioners said:

• There is no specific treatment for EHV-1, although antiviral drugs (i.e. valacyclovire) may have some value before neurological signs occur.

• Non-specific treatment may include intravenous fluids, and other appropriate supportive therapy.

• The use of anti-inflammatory drugs (NSAIDs) is strongly recommended.