Reining Horse Euthanized After EHV-1 Outbreak In Illinois

Two horses from the same stable tested positive for equine herpesvirus type 1 (EHV-1) after the Midwest Reining Horse Association show at Gordyville USA in Gifford, Illinois, May 2-3. One horse was successfully treated; the other was euthanized. As a result, Gorydville has closed for the recommended 21 days and is being thoroughly disinfected prior to reopening for equine events.

“We are in communication with the State of Illinois veterinarian as to the precautions/actions we are taking to disinfect our facility. It is closed for 21 days to equine events, recommended by the [Association of Equine Practitioners] AAEP,” stated an update on the Gordyville website. “The Illinois Youth show, May 15-17 is cancelled and possibly rescheduled this year, and the [National Barrel Horse Association] NBHA Great Lakes Finals, May 22-24, is cancelled and will reschedule in 2015. We encourage everyone at the show to stay home and observe for signs and symptoms. The welfare of our horses and clients are our main concern.”

According to the AAEP, EHV-1 is a virus that causes upper respiratory infection in young horses and can also cause abortion in pregnant mares. Adult horses that experience the respiratory form of EHV-1 may develop the neurological form of the disease, which affects the horse’s brain and spinal cord can result in paralysis and death.

Read more on EHV-1 from the AAEP.

Michigan EHV-1 Outbreak

An EHV-1 outbreak was documented in Michigan in April. On May 1, the Michigan Department of Agriculture and Rural Development issued a press release stating: “On April 28, MDARD released the Livingston County index farm where there were two positive horses (one was euthanized). There were also an additional two premises, one in Ionia County and one in Saginaw County, that had no EHV-1 positive horses but had had exposure to the index horse that were released from quarantine during the week of April 19. These farms were released from quarantine because the horses at the property had not exhibited fevers or signs consistent with EHV-1 for 28 consecutive days.

“There have been no new cases of EHV-1 since April 3, 2015. The number of EHV-1 cases of positive horses in Michigan has remained at four. Two positive horses mentioned above and two positive horses at a quarantined Saginaw County farm. This puts the total number of facilities under quarantine in Michigan due to EHV-1 at four. Horses at quarantined facilities are under quarantine until all horses have either had no fevers and/or clinical signs exhibited that are consistent with EHV-1 for 21 consecutive days and have subsequently tested negative for EHV-1 or have had no fevers and/or clinical signs exhibited that are consistent with EHV-1 for 28 consecutive days.”

Oregon EHV-1 Outbreak

Four Oregon horses have now tested positive for Equine Herpes Virus (EHV-1) with two of the horses showing neurological symptoms, according to an Oregon Department of Agriculture (ODA) press release on May 4. It was confirmed last week that a Marion County horse had tested positive for EHV-1 and had developed neurological symptoms. The second horse that developed neurological symptoms resided at a stable in Polk County with about 40 other horses and was taken to the Large Animal Hospital at Oregon State University’s College of Veterinary Medicine over the weekend. The Polk County stable has been placed under quarantine and the remaining horses are being monitored by the stable manager and a veterinarian.

In addition to the Polk County stable, two Marion County farms remain under quarantine due to exposure to EHV-1. The infected horses and other horses exposed at the quarantined facilities attended an Oregon High School Equestrian Team (OHSET) meet at the Linn County Fairgrounds on April 16-19. ODA is currently investigating the potential of any additional exposures at this time. In addition, ODA is working to notify owners of horses that have been potentially exposed and has notified Oregon equine veterinarians.