Another Suspected EHV Case in Maryland; Bowie Barn Under Hold Order

Edited press release
The Maryland Department of Agriculture placed an initial "Investigational Animal Hold Order" on Barn 1 at the Bowie Training Center Wednesday afternoon after a horse showed symptoms of equine herpesvirus. Equine herpesvirus-1 (also known as "rhino"), which causes upper respiratory infection, can also cause neurological disease.

The horse, trained by Chris Grove, had lameness after it last raced then began showing neurologic signs late last week. After discussions with his private veterinarian, the trainer decided to relocate his horse to an empty barn behind the Bowie grandstand as a precautionary measure. Grove indicated his horse was feeling energetic, "bucking and kicking" when he walked his horse to the isolated barn.

Blood samples and nasal swabs were taken on the horse Wednesday afternoon. Results should be available early next week. Until then none of the 29 horses in Grove's barn will be allowed to race at Laurel Park. Grove has elected not to train any of his horses until the results of the tests are revealed.

The former trainer of the horse in question told Maryland Jockey Club chief operating officer Lou Raffetto that he had been treating the horse for Equine Protozoal Myeloencephalitis. Grove did not know this when claiming the horse in November and the horse has been off the medicine since being claimed. This could be a reaction to being off the medicine.

(EPM is an infection of the central nervous system of horses. The neurologic signs that it causes are most commonly asymmetric incoordination (ataxia), weakness and spasticity, although they may mimic almost any neurologic condition. Clinical signs among horses with EPM include a wide array of symptoms that may result from primary or secondary problems. Some of the signs cannot be distinguished from other problems, such as lameness. Airway abnormalities, such as laryngeal hemiplegia (paralyzed flaps), dorsal displacement of the soft palate (snoring), or airway noise of undetermined origin may result from protozoa infecting the nerves which innervate the throat. Apparent lameness, particularly atypical lameness or slight gait asymmetry of the rear limbs are commonly caused by EPM. Focal muscle atrophy, or even generalized muscle atrophy or loss of condition may result. Secondary signs also occur with neurologic disease. Upward fixation of the patella (locking up of the stifle) is among the most common findings among horses with neurologic disease. Another common side effect of EPM is back soreness, which can be severe. Even typical racing injuries may ultimately be caused by EPM, because horses which are uncoordinated are much more likely to "take a bad step" in racing or training. Therefore, any horse with these signs should be carefully evaluated for the presence of neurologic disease).

Four horses have been euthanized at the major Maryland tracks this year, three at Pimlico Race Course and one at Laurel Park . Another horse was euthanized last week at a Kent County farm.

Eight horses remain isolated in the Pimlico Detention Barn suffering from various levels of the virus. Barns 5, 6, and A at Pimlico remain under state hold orders. The Maryland Jockey Club proactively placed the historic Baltimore oval on quarantine on Jan 21, restricting the movement of horses. There have been no new cases of EHV-1 at Pimlico since Jan 19.

At Laurel Park where live racing is being conducted, Barn 9 is also under a Hold Order. Rodney Jenkins, whose horses are stabled in that barn, will train the 35 horses he conditions inside the barn until the restrictions are lifted.

"Conditions at Pimlico and Laurel continue to progress in a positive manner," said Maryland state veterinarian Guy Hohenhaus. "Today's news at Bowie does not change our plans to try to clear Barn 5 at Pimlico next week after test results are returned."