frontier-airlines-pet-policy allows small cats and dogs to travel in the cabin as pets. Passengers must pay a non-refundable pet fee, and reservations should be made in advance due to limited availability. Pet carriers must fit under the seat and have a combined weight with the pet of no more than 40 pounds. Temperature restrictions apply. Emotional support animals are not accepted; only trained service animals are allowed. For the most accurate and current information, refer to Frontier Airlines' official website or contact their customer service.