When William Keegan, D.V.M., began his morning rounds on October 22 at Monmouth Park, he immediately realized that something was terribly wrong.

"I came into Barn 18 and five horses in a row had 102 and 103 fevers," Keegan said. "That's too atypical. Usually, you only see a couple of fevers, and they're contained to two- and three-year-olds. This ran the gamut from young horses to six- and seven-year-olds. I suspected that something was a little abnormal."

The suspicions and instinct of the Oceanport, New Jersey, resident currently in his 12th year of veterinary practice proved correct.

Four of the five horses eventually tested positive for equine herpesvirus (EHV-1). The disease is a form of the human herpes virus and produces myriad symptoms in horses, including respiratory problems, high fever, and abortions in pregnant mares.

In its most severe form, EHV-1 attacks a horse's neurological system and can lead to paralysis. Outbreaks of EHV-1 in December 2005 at Turfway Park and in January '06 at Pimlico Race Course and Laurel Park resulted in several equine deaths.

Keegan immediately grasped the severity of the evolving situation because EHV-1 can spread through a horse population as quickly as a cold travels through an elementary school.

"It's so contagious that it can be contracted by a droplet from two horses just coming in contact together," Keegan said. "It's so contagious that [the fevers] ran up one side of the barn and back in just a couple of days."

Keegan and fellow New Jersey veterinarian Bernard Dowd, D.V.M., took immediate steps to contain a large-scale outbreak.The gates of the Monmouth backstretch were closed the next day. No horses were allowed in or out except to race at the Meadowlands. That preventive measure occurred four days prior to positive test results, which prompted a full quarantine by the New Jersey Department of Agriculture.

"That saved the day," said trainer John Forbes, whose stable included 27 horses in one of the two quarantined barns. "Dr. Keegan and [Dr. Dowd] did a tremendous job, especially in the biohazard area."

"I don't know about that," Keegan said. "Maybe we just lessened the spread a little. We treated the horses with Valtrex, which is a human anti-virus medication."

Humans are immune from EHV-1 but they can easily spread the virus among horses. Monmouth placed disinfectant tubs of bleach at every barn entrance for dipping shoes. Movements of backstretch workers from one barn to another were limited, and people working in the affected barns were not permitted contact with other horses. The Meadowlands disinfected its paddock and starting gate after each race.

"Hand and foot traffic are vectors for the spread, so we really tried to limit that," Keegan said.

Veterinarians believe that a horse shipped from Canada brought the virus to Monmouth. Trainers affected included Justin Nixon, Tim Hills, and William Anderson. Their horses were treated and separated from the main horse population. They trained separately from the general horse population after normal training hours but were not permitted to  race.

Monmouth's stable area serves as a training center during the Meadowlands meet. Horses shipped to the Meadowlands in vans for each racing card, which only heightened the risk of spreading the virus. At one point, Monmouth quarantined all horses and lead ponies involved in an early-November outbreak at the Meadowlands when two spiked a fever. It was a false alarm, but when dealing with EHV-1, it is better to err on the side of caution, Keegan said.

"We were always concerned about a spread, but we were confident that we kept the virus contained in those two barns," Keegan said.

The New Jersey Department of Agriculture lifted the quarantine on November 9, allowing all but about 100 horses to leave New Jersey.

"We're waiting for the last batch of tests from the quarantine barns. If they come back negative, the state will [completely] lift the quarantine," Keegan said.--Tom De Martini