Does Frontier Airlines Allow Pets? Small dogs, cats, rabbits, guinea pigs, hamsters and small household birds can travel in the cabin provided they are in an FAA-approved carrier that fits under the seat. Pets are not permitted on international flights. Service animals are allowed without charge. Additional guidelines and restrictions apply so it's best to check their website before flying.
>https://www.flywithairline.com/blog/does-frontier-airlines-allow-pets/