Southwest Airlines Dog Flying: Cabin Fees, Carrier Rules, and Booking Steps

As of September 2026, Southwest Airlines dog flying means bringing a small, vaccinated domestic dog in the aircraft cabin only—never in cargo. Southwest Airlines, a U.S. passenger carrier, accepts dogs that are at least eight weeks old in a leak-proof carrier that fits under the seat, with a published Pet Fare of $125 per carrier each way on U.S. mainland routes according to Southwest Airlines Optional Travel Charges. Space is capped at six pet carriers per flight. This guide covers fees, carrier rules, booking steps, Hawaii and international limits, service-dog differences, and how digital livestock ID from Animal Passport differs from airline pet policies.

Published by Animal Passport. Last updated September 15, 2026.

What Southwest Airlines allows for dogs

Under the Southwest Airlines Contract of Carriage, Southwest may accept small vaccinated domestic cats and dogs at least eight (8) weeks old, contained in a pet carrier, and traveling with a passenger. One pet carrier may be allowed per passenger, and that carrier may contain up to two animals of the same species. Unaccompanied Minors may not travel with a pet. Southwest reserves the right to limit the number of pet carriers per flight to six (6), accepted on a first-come, first-served basis, according to the Southwest Airlines Contract of Carriage.

Southwest will not transport pets in the aircraft cargo compartments. That cabin-only rule is written into the same Contract of Carriage and is a core difference from airlines that still offer checked-pet or cargo options.

How much does Southwest Airlines dog flying cost?

Southwest publishes Pet Fare prices on its Optional Travel Charges page. As of the fees listed on that page, the one-way carry-on pet charge is:

Southwest Airlines states that the Pet Fare is subject to change at any time, must be paid at the Southwest ticket counter with accepted credit cards, and is refundable if you cancel the reservation, according to the Southwest Airlines Contract of Carriage and pet-policy help materials. The fee is charged per occupied pet carrier, not per dog, when two same-species pets share one carrier under Southwest’s rules.

Pet carrier rules for flying a dog on Southwest

All cabin pets must travel in an appropriate pet carrier and remain inside it at all times—including head and tail—while in the gate area, during boarding and deplaning, and onboard, according to the Southwest Airlines Contract of Carriage. Carriers must be leak-proof and well ventilated, and the dog must be able to stand up and move around the carrier with ease. The carrier must fit under the seat in front of the passenger and stay stowed there for the entire flight.

Passengers traveling with a pet may not occupy an exit row seat or a seat with no forward under-seat stowage, according to the Southwest Airlines Contract of Carriage. Southwest’s pet-carrier help article lists a Southwest pet carrier sized 15 inches long by 10 inches wide by 10 inches high, and other carriers with maximum dimensions of 18 inches long by 10.5 inches wide by 10 inches high, and recommends a soft-sided carrier because under-seat space varies by seat. Treat those figures as airline guidance and confirm the latest sizes on Southwest’s help center before you buy a carrier.

Pet carriers count as either a personal item or a carry-on item. Southwest’s airport pet guidance states you may board with either a pet carrier and a personal item or a pet carrier and a regular-size carry-on bag.

How to book and fly with a dog on Southwest: step by step

1. Confirm eligibility. Your dog must be a small, vaccinated domestic dog at least eight weeks old and able to remain calmly inside a compliant carrier for the full trip, per the Southwest Airlines Contract of Carriage.
2. Reserve the pet by phone. Pet reservations can only be booked by calling Southwest, according to the Southwest Airlines Contract of Carriage. Online booking alone does not secure pet space; flights are limited to six carriers.
3. Check destination rules early. No pets are accepted on itineraries between the continental United States and Hawaii, and no pets are accepted on international itineraries, according to the Southwest Airlines Contract of Carriage. Pets are accepted on flights between Hawaiian Islands under Southwest destination pet guidance, subject to state rules.
4. Check state or territory entry requirements. The United States Department of Agriculture Animal and Plant Health Inspection Service (USDA APHIS) states that APHIS does not regulate interstate movement of pets by their owners; receiving states and territories set health-certificate, vaccination, testing, or treatment rules. Contact a local veterinarian and check destination requirements as soon as travel is planned (USDA APHIS pet travel guidance, page last modified June 10, 2026).
5. Arrive at the ticket counter first. A passenger traveling with a pet must check the pet in at the airport ticket counter and pay the pet fare before proceeding to the departure gate, according to the Southwest Airlines Contract of Carriage.
6. Clear Transportation Security Administration (TSA) screening correctly. The TSA instructs travelers to remove the pet from the carrying case, place the empty case through the X-ray machine, maintain control of the pet with a leash, and remove the leash when carrying the pet through the metal detector; carriers may receive a visual and/or physical inspection (TSA FAQ and Small Pets screening pages).
7. Keep the dog in the carrier after security. Southwest airport pet guidance requires pets—including head and tail—to stay secured in the carrier in the gate area, during boarding and deplaning, and for the entire flight. Disruptive behavior such as excessive barking, growling, biting, or soiling the cabin or gate area may lead to denied boarding.
8. Board with your assigned group and stow under the seat. Do not choose an exit row. Southwest will not hold a flight for a pet relief-area visit, according to Southwest airport pet guidance.

Hawaii, Puerto Rico, and international limits

Two separate rule sets matter for Hawaii: Southwest’s airline rules and Hawaiʻi Department of Agriculture and Biosecurity quarantine rules.

Southwest airline rule: No pets are accepted on itineraries between the continental United States and Hawaii, according to the Southwest Airlines Contract of Carriage. Pets are not allowed on international flights or any itinerary that includes an international flight, according to Southwest destination pet guidance. Pets are accepted on flights between Hawaiian Islands, with a lower $35 per-carrier Pet Fare on Southwest’s Optional Travel Charges page.

State of Hawaiʻi rule: Hawaiʻi is rabies-free and requires dogs and cats entering the state from outside Hawaiʻi to complete quarantine pathways such as Direct Airport Release, 5 Day Or Less, or longer quarantine unless requirements are met, according to the Hawaiʻi Department of Agriculture and Biosecurity Animal Industry Division Quarantine FAQs. Those state entry rules are why mainland–Hawaii pet travel is not a simple airline add-on even on carriers that accept pets to Honolulu. Because Southwest does not accept pets on mainland–Hawaii itineraries, most travelers cannot use Southwest for that route with a pet dog.

Southwest destination pet guidance also notes that customers traveling to Puerto Rico may face specific requirements and should verify destination rules before travel.

Service dogs versus pet dogs on Southwest

Pet dogs and service dogs follow different legal and airline frameworks.

The U.S. Department of Transportation defines a service animal, under the Air Carrier Access Act, as a dog—regardless of breed or type—that is individually trained to do work or perform tasks for the benefit of a qualified individual with a disability. Emotional support animals, comfort animals, companionship animals, and service animals in training are not service animals under that DOT definition. Southwest’s Contract of Carriage states that Southwest permits fully trained service animals used by a qualified individual with a disability to accompany the passenger onboard at no charge, and that a completed DOT Service Animal Air Transportation Form must be provided.

Do not present an untrained companion dog as a service animal. Misrepresentation is not a workaround for Pet Fare or carrier rules, and disruptive animals may be refused transport under both DOT guidance and Southwest’s Contract of Carriage.

Health paperwork: airline rules are not the same as USDA APHIS export certificates

For typical owner-accompanied domestic travel inside the United States, USDA APHIS does not set a single federal interstate pet movement certificate requirement for owners. Destination states and territories do. That is why a health certificate that one state requires may not apply on another itinerary—always check the receiving jurisdiction (USDA APHIS).

Southwest’s eight-week minimum for cabin pets is an airline commercial policy in the Contract of Carriage. It is not a substitute for destination state or territory entry rules, and it is not an international USDA APHIS export health certificate.

International travel with a dog is outside Southwest’s pet program entirely: the Contract of Carriage states no pets will be accepted on international itineraries. If you need to leave the United States with a dog, you must use a carrier that accepts international pet travel and follow USDA APHIS country-specific export requirements plus destination import rules.

TSA screening tips that prevent delays

The Transportation Security Administration (TSA) allows small pets through the checkpoint subject to airline policy. Official TSA guidance is consistent across its Small Pets item page and pet-screening FAQ: remove the pet from the carrier, X-ray the empty carrier, control the pet on a leash, and remove the leash when you carry the animal through the metal detector. Never place a live animal in the X-ray tunnel. After screening, return the dog to the carrier away from the checkpoint flow so it cannot escape into the sterile area.

Southwest’s airport pet guidance aligns with that process: pay at the ticket counter first, then expect to hold your pet while the carrier is X-rayed. Plan extra time; pet check-in cannot be skipped at the gate.

Behavior, health, and safety limits

Southwest retains the right to refuse any pet that exhibits aggressive behavior or other characteristics incompatible with air travel, according to the Southwest Airlines Contract of Carriage. The Contract also states that pets must be healthy, harmless, inoffensive, odorless, and require no attention during the flight; oxygen or other first-aid procedures will not be administered to a pet; and in an emergency an oxygen mask will not be available for the pet. Southwest assumes no liability for the health or well-being of carry-on pets under that Contract language.

Practical preparation that matches those rules: acclimate the dog to the carrier before travel day, avoid overfeeding immediately before the flight, use absorbent bedding, and choose a nonstop itinerary when possible so the dog spends less time confined.

Animal Passport digital ID is not a Southwest pet ticket or government travel passport

Airline pet rules, USDA APHIS export paperwork, EU pet passports under the EU pet travel / PETS-style schemes, and commercial digital livestock identity products solve different problems. Confusing them causes denied boarding or false confidence about paperwork.

Animal Passport is a digital animal and livestock passport that uses muzzle biometrics—the nose print is unique, comparable to a fingerprint. Capture is phone-based. A record can bind owner, breed, estimated age, body condition, and vaccination history. Age can be estimated from a dental photograph with a confidence score, and body condition can be scored 1–5 from a side-profile photo. In August 2025, the product was used in livestock flood rescue in Pakistan so farmers could reclaim animals after paper tags washed away. More field notes appear on the Animal Passport blog.

Animal Passport is not a Southwest boarding credential, not a USDA APHIS-endorsed international health certificate, and not a government-issued EU pet passport unless an official authority separately adopts or recognizes a specific credential—which this product does not claim. Use Southwest and DOT processes for cabin travel; use Animal Passport when you need durable biometric identity and health-history records for animals, including livestock recovery scenarios.

Quick comparison: Southwest pet dog vs what you might assume

Checklist before you call Southwest

• Dog is at least eight weeks old, vaccinated, and calm in a soft-sided under-seat carrier.
• You can travel as a ticketed adult passenger (not as an Unaccompanied Minor with a pet).
• Your itinerary is domestic U.S. mainland or interisland Hawaiʻi—not mainland–Hawaii, not international.
• You have checked destination state or territory entry rules via USDA APHIS links and the state animal health official if needed.
• You planned ticket-counter time to pay the Pet Fare and TSA time to remove the dog from the carrier for screening.
• You understand service-dog rules are different and require DOT forms when traveling as a service animal.

For ongoing livestock-identity reporting and animal travel explainers, see Animal Passport blogs. Always re-check Southwest Optional Travel Charges and the Contract of Carriage close to departure; Pet Fare and operational limits can change.