Air Canada is preparing to become the country's first airline to ban pets from its cabins on domestic flights as its controversial Sept. 18 deadline approaches.

The decision to carry pets in the airplanes' cargo holds has separated pet owners and allergy sufferers into opposing camps. Animal rights advocates say poor ventilation and air pressure changes can make for a stressful experience for pets. But others say pets in the cabin can trigger allergy attacks and impair breathing.

Air Canada spokesman Peter Fitzpatrick told CBC that the airline made the decision to protect the health and safety of its travellers. The decision was in part prompted by a series of complaints about pets in the cabin filed with the Canadian Transportation Agency, he said.

The ban standardizes Air Canada's rules, Fitzpatrick said, noting that pets haven't been allowed in cabins on international flights for many years.

"We've had a lot of positive feedback," he said.

Guide dogs are the sole exception to the ban and will continue to be allowed in the cabin to assist their owners.

Fitzpatrick suggests that travellers may check their animals as luggage or use the airline's live animal travel program operated by skilled workers.

"They get all kinds [of animals], llamas from Peru and rare birds and horses," Fitzpatrick said. "They can deal with a whole gamut of animals, they're quite expert at that."

However, Michael O'Sullivan, executive director of the Humane Society of Canada, said that the airline's ban is unreasonable. He said allergic reactions to animals are unlikely unless a person has direct contact with an animal.

O'Sullivan also said it's extremely stressful for pets to be held in the cargo area.

"The rule is supposed to be that they're the last loaded on the plane and the first loaded off but airports are really busy places. Sometimes one handler is not as capable as the next, and sometimes the holds are not properly heated," he said.

WestJet Airlines continues to allow pets in airplane cabins on domestic flights. Travellers may bring cats, dogs, birds and rabbits in leak-proof kennels that fit under the seat.

With files from the Canadian Press