"This is pretty serious," said State Veterinarian Don Hoenig on Friday, after issuing an emergency bulletin to alert Maine's horse industry.

One horse, a 17-year-old, died on March 18 of what appeared to be the neurological form of equine herpes virus Type 1, or EHV-1, and a second horse, a 3-year-old gelding, was euthanized a day later.

A third horse is being treated for EHV-1 and is responding well, Hoenig said Friday.

All three of the contaminated horses had been housed at a stable in Rome. The horse that is being treated has since been moved to a stable in Wales. Both the Rome and Wales stables are now under quarantine.

Hoenig said the state for three years has been watching EHV-1 affect horses throughout the Midwest and on the East Coast, including Connecticut and New Hampshire, and in several Canadian provinces.

It was EHV-1's presence in New Brunswick and Nova Scotia that concerned Hoenig. "We have a large number of horses that move back and forth to our racetracks," he said.

Hoenig created a task force within the Maine Department of Agriculture and wrote letters of concern to Maine's horse owners in 2005, 2006 and again in 2007.

"On March 9, before we knew the disease was in Maine, we strongly recommended to all agricultural fairs, training facilities and racetracks to require vaccinations for EHV-1 not less than 14 days or more than six months for any horse," Hoenig said.

It was too late, however, because the disease was already in the state.

Although all three horses are suspected of having the contagious disease, it has been confirmed only in the horse that was euthanized. Hoenig said both stables have been quarantined and no people or horses will be allowed in or out for at least 21 days.

He said the last time a horse had been moved into the Rome stable was October 2006. "The disease can remain within the horse in a latent stage and then come out when the animal is under stress," he said.

Hoenig called the disease "very nasty. The horses die very quickly. It's ugly."

He assured horse owners that the disease is not contagious to humans or to other animals. It is spread from horse to horse through respiratory secretions, not through the air, and the virus can survive outside a host for a while. Therefore, equipment, water buckets, even caretakers' clothing can be contaminated. Pregnant horses with EHV-1 often abort and the fetus also is contaminated.

Hoenig said the vaccination for EHV-1 has questionable ability to protect against the neurological form of the disease.

He said a primary symptom of the disease is lethargy. "The horse will become unable to stand, have uncoordinated hind and front legs, and many die if not euthanized first," he said.

Before 2003, reports of EHV-1 in the United States were sporadic, with none to few outbreaks annually. In 2005, seven outbreaks were reported in five states, and by 2006, there were 11 outbreaks in eight states.

All horse owners are encouraged to consult with their veterinarians on recommendations concerning vaccination and monitoring for the disease.

More information can be found at www.aphis.usda.gov/vs/nahss/equine/ehv.
"This content originally appeared as a copyrighted article in the Monday, April 02, 2007 edition of the Bangor Daily NEWS and is used here with permission."