I guess things have changed in the last few years. I had to transport my daughter's cats when she & her husband were going to Iraq. We left Ft. Riley and drove the cats in their pet carriers to Kansas International Airport. They were taken to baggage claim where the airport crew took over. We didn't see them again until we arrived at our destination, picking them up at baggage claim.
Hey, maybe there's a little kitty TSA somewhere under the terminal!
Pets in the cabin
Our cabins are pet friendly! You can bring your cat or small dog in the cabin with you provided it is small enough to fit and stay comfortably in its carrier under the seat in front of you, and you are travelling on:
A flight operated by Air Canada
An Air Canada Express flight operated by Jazz or Air Georgian
An Air Canada Express flight operated by Sky Regional between Montreal and Toronto City Airport (YTZ).
http://www.aircanada.com/en/travelinfo/airport/baggage/pets-in-cabin.html