Turf Paradise Racetrack Quarantined Due to Potential EHV-1

Turf Paradise Racetrack Quarantined Due to Potential EHV-1

In many horses, fever is the only sign of EHV-1 infection, which can go undetected.

Photo: Stephanie L. Church, Editor-in-Chief

The Arizona Department of Agriculture announced on Jan. 28 that it has quarantined horses at Turf Paradise racetrack, in Phoenix, after determining that three horses could have been exposed to equine herpesvirus-1 (EHV-1).

The quarantine requires all horses at the track to stay in place and for no horses to come onto the property for at least 21 days.

The quarantine follows three horses coming into the state from Dona Ana County, New Mexico, where several horses have been diagnosed with EHV-1. The New Mexico Livestock Board issued a quarantine for several locations, but the horses at Turf Paradise left before the restrictions were in place.

Turf Paradise immediately isolated the three horses following that disease report and monitored them for clinical signs. The track is also requiring strict biosecurity measures for all horse owners and personnel at the track.

“This virus type can cause severe neurological symptoms, which one of the horses that came from New Mexico developed,” said Acting State Veterinarian Sue Gale, DVM. “The case is not confirmed by testing yet, but is considered to be probable case of the virus.”

Herpesvirus is highly contagious among horses and can cause a variety of ailments in equids, including rhinopneumonitis (a respiratory disease usually found in young horses), abortion in broodmares, and myeloencephalopathy (the neurologic form). In many horses, fever is the only sign of EHV-1 infection, which can go undetected.

In addition to fever, other common signs of EHV-1 infection in young horses include cough, decreased appetite, depression, and a nasal discharge. Pregnant mares typically show no signs of infection before they abort, and abortions usually occur late in gestation (around eight months), but can be earlier. Abortions can occur anywhere from two weeks to several months following infection with EHV-1.

Horses with the neurologic form usually have a fever at the onset of the disease and might show signs of a respiratory infection. A few days later, neurologic signs such as ataxia (incoordination), weakness or paralysis of the fore- and hind limbs, urine retention and dribbling, loss of tail tone, and recumbency (inability to rise) develop.

“If horse owners notice these symptoms, they should contact their personal vet,” said Gale. “If veterinarians see a horse with these symptoms, they need to report the case to the state veterinarian.

Officials at Turf Paradise say the track will remain open and that there is no concern for people who attend the races. Officials with the Department of Agriculture, Arizona Racing Commission, and Turf Paradise will continue to work together to resolve the issue.

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