British Horseracing Authority Monitoring EHV-1 Outbreak

British racehorse trainer Victor Dartnall is currently dealing with an outbreak of neurologic equine herpesvirus-1 (EHV-1) at his yard in North Devon, England.

"Over the last few day we have had a significant outbreak of what was a suspected herpes virus," he said in a Nov. 15 statement on his website. "Today the initial lab results support the cause of the problem to be neurological herpes virus. We are working closely with our vets and the (British Horseracing Authority) and are very hopeful that the situation is coming under control."

In a Nov. 15 British Horseracing Authority (BHA) press release, Tim Morris DVM, PhD, BHA director of equine science and welfare, said, "We have been working with the trainer and his veterinary surgeon to ensure that the correct, robust security measures have been put in place. It is, in theory, possible that horses may have been infectious before the signs of the disease appeared. We have therefore alerted racecourse, trainer. and veterinary representatives to possible exposure but stress that the actual risk of transmission of this virus in a controlled race-day environment is relatively small.

"This emphasizes the importance of trainers being vigilant for signs of disease and in particular they should refer to the recently published National Trainers Federation Code of Practice for Infectious Diseases of Racehorses in Training, which contains specific advice on surveillance for this disease and what to do if they have concerns that a horse in their care is showing signs of the disease," Morris added.

Although it's not transmissible to humans, EHV-1 is highly contagious among horses and camelids, and it is generally passed from horse to horse via aerosol transmission (when affected animals sneeze/cough) and contact with nasal secretions. The disease can cause a variety of ailments in equines, including rhinopneumonitis (a respiratory disease usually found in young horses), abortion in broodmares, and myeloencephalopathy (EHM, the neurologic form).

Myeloencephalopathy is characterized by fever, ataxia (incoordination), weakness or paralysis of the hind limbs, and incontinence. Should a horse with potential EHV-1 exposure display any of the aforementioned clinical signs, a veterinarian should be called to obtain samples and test for the disease.

Disclaimer: Seek the advice of a qualified veterinarian before proceeding with any diagnosis, treatment, or therapy.