YARMOUTH — “Ready to work, Cinder?” asked Capt. Cynthia Michaels of the Dallas Fire Department as she led her Labrador retriever from falling snow into the two-story home that had been gutted by flames the week before.

Caught up in the game the two had been playing, Cinder responded with the playful enthusiasm that typifies her breed.

Holding the dog’s leash in one hand, Michaels repeatedly jabbed the blackened floor with the index finger of the other. “Seek. Seek. Seek. Seek,” she commanded as Cinder’s sentient nose got down to business.

In the burned-out shell of what had once been a downstairs living room, Cinder detected the scents her trainers had imprinted during classroom sessions weeks earlier.

“Show me. Show me,” Michaels said, prodding the 60-pound black Lab to pinpoint the spot where the instructor had planted a drop of gasoline. Taking the cue from her handler, Cinder sat directly on the spot.

Her reward came instantly: a handful of kibbles that Michaels pulled out of her waist pack.

If the fire scene had actually been under investigation, officials would have removed a test sample from the spot and sent it to a laboratory for analysis. But for now, the charred dwelling near Casco Bay offered an opportunity for Cinder and her canine classmates to test their skills amid the acrid smells and fire debris of an actual burn site.

The dogs, earmarked for duty in Dallas, Shreveport, La., Columbus, Ohio, and the fire division in the office of Georgia’s Commissioner of Insurance, comprise the first class to be trained under an agreement between State Farm Insurance Companies and the Maine Criminal Justice Academy.

Also being trained at the same time were dogs for the West Side Fire Department in Florida’s Manatee County and the New Hampshire Fire Marshal’s Office in Concord.

Most of the dogs in the program are donated by breeders or individuals who for one reason or another can no longer keep their pets. Labradors are the breed of choice because they offer a sensitive nose along with the agility to rummage through fire debris as well as a disposition that enables them to spend hour after hour in a sleuthing process that they regard as a game.

Investigator Tom Norton, of Plainfield, N.H., just made a household pet of his arson dog who put in three years of service.

“She developed some personality problem. She decided she’s afraid of burned-out buildings,” said Norton, who has no idea why.

Norton was with the class to train a replacement, also named Cinder and referred to as Cinder 2 to differentiate her from Michaels’ dog.

The investigators were introduced to their dogs on arrival at the training school in Alfred. Handlers seemed to bond quickly to the dogs and looked forward to bringing them into their homes.

“My 7-year-old girl can’t wait to meet him,” said Capt. William Alberta of the Shreveport Fire Department, petting his yellow Lab, Jack.

State Farm plans to finance the training of as many as 36 of the accelerant detection dogs — known more familiarly as arson dogs — over the next three years.

Seeking to combat the costly and sometimes deadly crime of arson, the insurer scrutinized dog training programs nationwide and found that the one in Maine was held in universally high esteem.

“Everybody would say, `Take a look at Maine’s program. It’s the one that really works,’ ” recalled Ron Arnold, a State Farm official who visited the training session.

State Farm finances training costs, room and board and travel to and from the school. The law enforcement agency continues to pay the salary of the arson investigator who will become the dog’s handler.

At the end of the five-week course, a Maine chemist certifies that each dog can discriminate among various accelerants used to start fires. Such certification is important because evidence that the dog helps to uncover can be used in civil and criminal trials.

Trooper Paul Gallagher, head canine trainer for the Maine State Police, says the value of the dogs lies in their ability to sniff out petrochemicals at a fire scene quickly and accurately.

“This saves us digging time and it saves us the trouble of having to return to the scene,” he said.

A Maine arson dog proved its worth last December when it was brought to the scene of an apartment house fire in Portland that claimed four lives. Maddy, a cross between a yellow Lab and a greyhound, detected an accelerant on the shoes of a youth, enabling investigators to arrest him.

Eight-year-old Maddy, the oldest of the 100 or so arson dogs in service nationwide, has a perfect detection record.

“She’s never given a false indication. Out of some 40-odd cases that were sent to the lab, all have come back with some type of accelerant,” said Bob Long of the Maine Fire Marshal’s Office.

Demand for training is heavy and State Farm says applicants for the course are being selected from a waiting list according to which agency’s needs are most pressing. Those selected for the next class include fire departments in Oakland, Calif., and Phoenix.

The current crop of handlers expect to face a heavy workload when they return to duty.

“She’ll be a very busy dog,” Michaels said of Dallas-bound Cinder. “We’ll be a very busy team.”