When traveling with pets on American Airlines, the carry-on fee is $125 per kennel for dogs and cats. This applies to flights across the U.S., Canada, Mexico, and several other destinations. There are specific size and weight restrictions, and pets must be able to stay in a carrier under the seat. Since only a limited number of pets are allowed in the cabin, contact American Airlines as soon as you book your ticket. Visit their website to learn more and reserve your spot.