Last winter, with his chain frozen to the ground and owners out of town on a weekend that saw temperatures at around 7 degrees, a mixed-breed dog kept out in a yard in Bowdoin was freezing to death, unable to eat, drink or move.

Animal control officer Clifford Daigle was alerted by a neighbor’s call, seized the dog — likely saving his life — and filed animal cruelty charges against the owners. “The children were growing up and the family really no longer cared about him,” Daigle said.

Each year, the state investigates dozens of complaints about pets left out in frigid conditions that can lead to hypothermia, frostbite and even death. There are no statewide figures available on complaints filed and rescues made, but authorities say it happens every year.

“We’ve had dogs that have frozen to death that people have abandoned outside the shelter in 20- or 30-degree-below-zero weather,” Steve Dostie, Greater Androscoggin Humane Society executive director, said. “You have to remember that animals — you just can’t leave them outdoors for long periods of time in really cold, frigid weather. You definitely don’t want to put your animal out and tie him to a tree and leave him there for hours on end in 10-degree weather.”

Laws governing adequate shelter vary from state to state. While Maine law provides basic standards for shelter that include three-sided housing and a waterproof roof, experts say in all instances common sense should prevail.

Amy Dugan, president of the board of the Wilderness Sled Dog Racing Association in Greenville and owner of 20 sled dogs, said not all dogs are equipped for the cold. “If there’s a short-coated breed and the dog has no purpose being outside, I don’t think it’s right,” she said in regard to keeping pets outdoors in winter.

“They have to be a certain breed and must be acclimated to the climate to be able to stay outside like they do,” she explained, noting her dogs have double coats and include Alaskan huskies, Siberian huskies and Alaskan Malamutes. Even so, Dugan’s dogs find shelter and warmth in specially constructed, individual dog houses that include a small opening away from the wind with three layers of straw for insulation.

Dugan’s dogs are also given more food in below-zero temperatures. The food  includes added fat, such as a quarter stick of butter or pork fat. “This generates heat, so that’s how they survive,” she said. The difference between the aptly named Arctic breeds and most others is that the former are bred to be outside, Dugan noted.

Dr. Christine Fraser, state veterinarian since 2003, said that under Maine law animals seen shivering for a continuous 10 minutes, or showing signs of frostbite or hypothermia, can be seized. The owner may also be charged with failing to provide adequate shelter and face the state-mandated minimum fine of $500.

“We come across people that have a dog that is an inappropriate breed to be outside: a pit bull or greyhound or great Dane, all with thin coats,” she said. The first thing her program does is try and fix the problem directly with the owner.

“We handle things on a case-by-case basis, explaining to the owner that certain animals are not meant to live out in the cold as they cannot maintain their body temperature,” Fraser said. Because of the law, which is not breed specific, “until the animal shows some sort of detrimental health effects, we can’t do more than watch and monitor if there’s really a concern.”

Dr. Forest Clark, owner of Lewiston Veterinary Hospital, has seen his share of hypothermic and frostbitten animals. Signs may include listlessness and unresponsiveness, as the cold slows down bodily functions, and the dog may not move or bark as he usually does, for example, when someone enters the yard.

“The first place you start to see frostbite is on the margins of the ear, and I’ve seen animals come in and half of their ear is dead,” he said. “We have to take it off.” Referencing cats, Clark noted people have brought in strays that had been found perhaps a year after a frostbite episode, where the dead part of the ear had fallen off leaving almost no ear flap at all.

With an animal’s ears, nose, tail (particularly the tip), foot pads and any exposed areas such as the stomach, skin can freeze in as few as 20 minutes in subzero and even single-digit temperatures.

“If you’ve got more than one animal, they often huddle together to keep each other warm,” Clark said. “But if you had three or four dachshunds outside overnight, that would be bad news because they just couldn’t do it.”

Lewiston animal control officer Wendall Strout recently dealt with someone who was leaving their dog in their vehicle daily at their workplace for weeks at a time. Under Maine law, a vehicle cannot be used as housing, in part because its interior can become a refrigerator or freezer in winter temperatures. The idea of cruelty in this instance was in question after Strout checked the animal, found that it was not living in the vehicle and exhibited no evidence of shivering for 10 consecutive minutes. However, Strout did ultimately order the owner to discontinue the action.

In the Lisbon area, animal control officer Jeff Cooper recalled a report where an owner had a doghouse for their dog, but with no floor. The animal was forced to sleep on frozen ground. “A lot of people just need to be educated, so you try and work with them,” Cooper said of his cruelty enforcement efforts. “I try and work with everybody first, but if they don’t want to work with me, then I’ll let them work with the judge,” he said, noting his 100 percent conviction rate.

“I think the best resource or guidance about if your dog can be left out in the weather . . . is talk to your veterinarian,” state veterinarian Fraser said. “Ask about your dog’s tolerances. The veterinarian has examined the animal and knows more about him — can evaluate if the dog is thin or geriatric or has a disease that might compromise the animal.”

Observation and common sense are also key, she said, explaining some dogs will lay out in a blizzard and won’t even want to come in, while others are just miserable. “Try to be receptive to what your animal is showing you.”

If signs of hypothermia or frostbite are observed in your pet, the longer he is cold, the more danger he is in. Wrap in blankets or coats and seek immediate veterinary intervention. If help is not available:

— Bring inside and wrap in blankets. Fill large bottles (like soda bottles) with warm water. Make sure they are not so hot that you cannot touch them; warming the animal too fast can have adverse effects. Put bottles under blankets. A heating pad wrapped in a towel (so it does not come in contact with the dog’s skin with the potential of burning) can also be used.

— If the animal is wet, heat loss is compounded, so dry off quickly and proceed as above.