Unidentified Horse Disease In Hong Kong

From mid-April through the beginning of May, an unidentified disease affected racehorses and riding school horses in Hong Kong. Symptoms were very mild and included inappetence and fever (pyrexia). Horses usually regained their normal appetite and temperature within a day or two. The last cases were reported May 15.

The Animal Health Trust reported 22 of the 25 flat-racing Thoroughbred training stables at Sha Tin Racecourse and training complex reported that 132 horses went off their feed and 31 horses exhibited a mild to moderate pyrexia. Six of Hong Kong's nine riding schools reported 54 horses off their feed and 18 with pyrexia.

The Department of Microbiology of the University of Hong Kong has isolated equine herpesvirus-1 (EHV-1) from six of the nasopharyngeal swabs taken from infected horses, but there is still some speculation as to whether EHV-1 is what caused the symptoms.The most recent outbreak of EHV-1 in Hong Kong was in 1997.

"The preliminary diagnosis of EHV-1 based on virus culture has not been confirmed upon paired serology, and PCR tests of the viral isolate failed to confirm both EHV-1 and EHV-4 (herpesvirus-4)," says Keith L. Watkins, BVSc, MRCVS, Senior Veterinary Surgeon for the Hong Kong Jockey Club. "Tests are continuing both in Hong Kong and the U.K. to try and establish the etiology of the syndrome, which was characterized only by mild inappetence and pyrexia," he adds.

Movement restrictions temporarily have been placed on horses within the territory.

About the Author

Stephanie L. Church, Editor-in-Chief

Stephanie L. Church, Editor-in-Chief, received a B.A. in Journalism and Equestrian Studies from Averett College in Danville, Virginia. A Pony Club and 4-H graduate, her background is in eventing, and she is schooling her recently retired Thoroughbred racehorse, Happy, toward a career in that discipline. She also enjoys traveling, photography, cycling, and cooking in her free time.

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