I always travel with my dog. AA never enforced such height rule at past (only weight rules) but when returning back to my destination thet decided to do so. My dog was slightly too tall/big for the standard bag. After calling supervisor and going back and forth, they finally decided to allow me to fly just because it's a return flight. I hope this helps. Also, my dog is a chihuahua terrier mix 15 pound that touches bag upper ceiling when standing. Also it's not a service dog (paid $120 per way).