Pets in kennels or cages previously had to travel as checked baggage. (Canadian Press)

Dogs and cats in containers can now join their owners in executive or economy class on Air Canada flights.

Starting Wednesday, pets in approved carriers are allowed on both regular Air Canada and regional Jazz flights, provided the container fits under the seat.

The decision to allow pets on board was announced last month. Pets in kennels or cages previously had to travel as checked baggage.

Travellers are required to pre-register their pets with Air Canada reservations within 24 hours of booking a ticket, and pay a $50 fee each way within Canada and the U.S., or $100 each way on international flights. Only one pet is allowed on board for each traveller.

Only two to four pets will be allowed in the cabin on each flight, out of consideration for passengers who are allergic to animals, the airline said.

Pets in carriers may also travel as checked baggage on flights where temperature-controlled and ventilated baggage compartments are available for a fee of $105 each way within Canada and the U.S. or $270 each way on international flights.