TORONTO — There's bad news for Air Canada travellers who want to bring their cherished pets along with them on the plane for their summer vacation.

The Montreal-based airline said Thursday that as of July 15, Bowser and Muffy won't be allowed on its domestic passenger flights.

And pending approval from the Canadian Transportation Agency, pets won't be accepted for flights to the U.S. or other international destinations.

Dogs, cats and other pets will have to be shipped on cargo planes.

Peter Fitzpatrick, a Toronto-based spokesman for Air Canada, said the airline is so full with bookings, it needs more room to carry baggage, so pets will have to go cargo. He said it's a matter of improving customer service.

"We've had record load factors for the past three years. That means our planes have been fuller than they've ever been. And this fact, combined with the new security requirements that limit gels and liquids people can take on a plane have meant we're carrying much more luggage than we have in the past,'' said Fitzpatrick.

With Air Canada's load factor running at more than 80 per cent, he said animals in the hold restrict the amount of luggage the airline can carry, because animals need extra room for air and ventilation.

"So essentially it comes down to a question of carrying bags for the vast majority of our customers or carrying pets for a smaller number of our passengers,'' he said.

Fitpatrick couldn't provide an exact figure for the number of passengers who would be affected by the change but said it's a small minority of customers.

Air Canada is not the only airline with a no-fly rule for pets but the policy varies among airlines.

Southwest Airlines said Thursday it does not allow pets on its planes.

A British Airways spokesman said British Airways does allow pets on passenger flights, but only in the cargo hold. Both JetBlue and Lufthansa said they do permit cats and small dogs in the cabin. WestJet accepts small dogs, cats, rabbits and birds in the cabin on domestic and transborder flights.

"So this isn't unusual for the industry. In fact it's increasingly becoming the standard,'' said Fitzpatrick.

He admitted it will be an inconvenience for the small number of people who do want to take their pets with them but said they can still use Air Canada cargo services and ship their animal that way.

Last September 18th, there were howls of outrage from pet owners when Air Canada sent pets packing from the cabin to the cargo hold, but allergy sufferers were breathing sighs of relief.

Fitzpatrick said the new policy will not apply to guide dogs for the blind. And people who have already bought tickets, or are buying tickets up until July 15, will be allowed to bring along their pets in the cargo hold.

He said Air Canada can make the change to its domestic flights without the agency's approval, but needs approval from the agency to make the change for international flights.

Air Canada carries 34 million passengers each year.