WASHINGTON — Two or three times a week, Christine Murray’s dog, a pit bull and beagle mix named Annie, leaps onto Murray’s lap and begins licking her face furiously.

It’s not a sign of affection or misbehavior, Murray says, but a warning to the dog’s owner to stop what she’s doing and lie down.

One or two minutes later, says the 28-year-old Leesburg, Va., resident, she will be racked by an epileptic seizure that can leave her shaking uncontrollably for 10 minutes or more.

“It’s amazing,” she says. “I can’t explain it. I don’t know why. But Annie can tell when I’m going to have a seizure” — which is something that Murray, like most epileptics, wouldn’t otherwise know.

Though Murray and dozens of other epileptics make such claims about their dogs, seizure-alerting canines are a relatively new phenomenon backed by little scientific proof, medical experts say.

In Murray’s case, the skepticism extends to some local store and restaurant owners, who have refused to recognize Annie as a disability-service dog and have banned the animal from their premises.

“I’ve had people come up to me in stores and say, `Get that filthy mutt of out here,’ ” said Murray, who never keeps Annie more than a few feet away. “I try to tell them it’s a seizure dog, but they don’t believe me.”

Unlike other service animals, such as guide dogs for blind people, seizure-alerting dogs generally do not have formal academy training. Murray discovered her dog’s abilities by accident and later put the animal through a home obedience-training program.

Loudoun County’s public-transit service won’t let Annie on board its buses.

Federal law allows service dogs in any public building but does not spell out what kind of certification the animals require.

Adding to the controversy is a dearth of research into seizure-alerting dogs. The Epilepsy Foundation of America, for example, does not formally recognize such claims, spokesman Peter Van Haverbeke said.

“We’re really open-minded on the issue, but until there’s some more research, we really don’t have a position on it,” he said.

Despite the lack of scientific evidence, animal-behavior experts and epilepsy researchers see merit in claims of people such as Murray. They speculate that the dogs are responding to slight changes in the human body that lead up to a seizure, which is a series of rapid electrical discharges in the brain that can cause violent convulsions.

Some researchers suggest that dogs are able to sense changes in muscle tone and smell other physiological transformations that are undetectable to humans, said Pamela Conford, director of the New York-based Epilepsy Institute, which is studying such claims.

Ruby Joyce, who heads Sheppy’s Disability Dogs Inc. in Waterboro, Maine, the home-training program in which Annie was enrolled, said she is aware of about 600 such animals nationwide.

“It sounds fake to a lot of people, but it’s the most remarkable thing you’ll ever see,” Joyce said. In addition to alerting owners, some dogs will make sure that nothing is covering their owners’ mouths and will help turn prone people on their sides during a seizure, she said.

Dogs can alert their owners through barking, staring or licking, Joyce said.

In Greg Binder’s case, a tiny Manchester terrier named Rip alerts the 22-year-old Reston, Va., resident to seizures with a high-pitched bark three or four minutes before Binder’s convulsions.

Binder’s mother, Patricia, who lives with him, said Rip has warned her son about every major seizure he has had in the last five years. “There’s no doubt about it. The dog has changed his life,” she said.

Murray recently purchased a bright orange leash and harness and made a sign reading, “Seizure Alert Dog. I am working. Please don’t pet me.” For Murray, whose epilepsy cannot be controlled by medication, having Annie constantly at her side for the last three years has given her a sense of newfound freedom.

“I never used to leave the house, because I was afraid I’d hurt myself or people would think I was crazy if I suddenly had a seizure in a public place,” she said.

Now, she says, she goes shopping, eats out and visits friends. Several times this year, Murray said, Annie’s warnings have kept her from collapsing in the middle of a street or falling down stairs.