I've heard that some airlines have breed restrictions due to breathing problems...I'm flying USAir and I didn't see anything on their site, but I'm worried. My puppy will be about 4m old when we plan to travel.

I have not flown with mine yet but I would only fly with him in the cabin. If you fly with your dog in the cabin, there should be no problems with being a squishy-faced dog. I hear Sturdibags are really good for flying because they are flexible and fit nicely under the seat. You probably need to call USAir and inform them that you'll have a dog and you'll need to purchase a ticket for him when you get there. Good luck with everything!

thank you...does anyone know if the "small" sturdibag would fit my 4m old Boston Terrier? The dimensions are 18"L x 10"H x 10"W. This is the largest size bag that I could find that the airline would approve to carry on...

Delta airlines will only allow BTs and other snub nose dogs to ride in the cabin. And they charge $150 each way. They need to be approved in advance because only a limited number of animals are allowed.

katpin84, small size should be fine for the pup. the rule is that the dog should be able to stand up inside the bag, but there shouldn't be a lot of extra space above her.
we took one flight, transcontinental, by Delta. i had Patsy inside her sherpabag, underneath the seat. no problems with breathing whatsoever. i also took her regularly to the bathroom (paper training helps a lot in these situations) - both to pee and to just get out of the bag, since they wouldn't allow the dog to be out at all, even briefly.

I booked a trip with my dog for Thanksgiving. He's 24 lbs. and I got the large. It is taller than the size stated on the website but it is flexible and am told by several others with BTs that it will fit nicely under the seat.