Southwest Airline Dog Policy: Cabin Fees, Carriers, and Service Dogs

As of September 2026, the Southwest airline dog policy lets small, vaccinated domestic dogs fly in the cabin only—never cargo—if they are at least eight weeks old, stay fully inside an under-seat carrier, and you book by phone and pay at the ticket counter. Southwest Airlines’ Optional Travel Charges list $125 per carrier one-way on U.S. mainland flights and $35 between Hawaiian Islands. Pets are barred on international flights and mainland–Hawaii itineraries.

The Southwest airline dog policy is Southwest Airlines’ official rules for pet dogs and trained service dogs on its network. Those carrier and destination rules are separate from Animal Passport, a digital animal and livestock identity product that uses muzzle biometrics—not a government pet passport or airline boarding document.

What the Southwest airline dog policy covers

Southwest Airlines’ Contract of Carriage (section on pets) states that Southwest may accept small vaccinated domestic cats and dogs that are at least eight (8) weeks old, contained in a pet carrier, and traveling with a passenger. One pet carrier is allowed per passenger, and that carrier may hold up to two animals of the same species. Unaccompanied minors may not travel with a pet. Southwest reserves the right to limit pet carriers to six per flight, accepted on a first-come, first-served basis.

Southwest will not transport pets in aircraft cargo compartments. That cabin-only rule is a defining feature of the Southwest airline dog policy and differs from some other U.S. carriers that still offer checked-pet programs under temperature and route restrictions.

How much does Southwest charge to fly a dog?

On Southwest Airlines’ Optional Travel Charges page, the one-way carry-on pet charge is listed as:

• $125 per pet carrier on U.S. mainland flights
• $35 per pet carrier between Hawaiian Islands

Southwest Airlines notes that the pet fare is subject to change at any time, that each pet carrier counts as a carry-on or personal item, and that only small vaccinated domestic cats and dogs are accepted as pets. The Contract of Carriage adds that pet reservations can only be booked by calling Southwest, the pet fare must be collected at the airport ticket counter, the passenger must check the pet in at the ticket counter and pay before going to the gate, and the pet fare is refundable if the reservation is canceled.

Pet carrier and cabin rules

Under Southwest Airlines’ Contract of Carriage, cabin pets must:

1. Travel in an appropriate pet carrier that is leak-proof and well ventilated
2. Remain completely inside the carrier—including head and tail—in the gate area, during boarding and deplaning, and onboard
3. Be able to stand up and move around inside the carrier with ease
4. 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. Southwest may refuse a pet that shows aggressive or otherwise incompatible behavior, and the carrier states that pets must be healthy, harmless, inoffensive, odorless, and require no attention during flight. The Contract of Carriage also warns that oxygen or other first-aid procedures will not be administered to a pet if the animal becomes ill, and that an oxygen mask will not be available for the pet in an emergency.

Southwest assumes no liability for the health or wellbeing of carry-on pets, according to Southwest Airlines’ Contract of Carriage.

Because under-seat space varies by seat and aircraft, soft-sided carriers are commonly preferred by travelers; always confirm the current carrier-size guidance on Southwest’s official pet-carrier help pages before you fly.

Destination limits: Hawaii, Puerto Rico, and international

Hawaii

Southwest Airlines’ Contract of Carriage states that no pets are accepted on itineraries between the continental United States and Hawaii. Pets may travel on flights between Hawaiian Islands, with the lower $35 one-way pet charge listed on Southwest’s Optional Travel Charges page.

That mainland-to-Hawaii ban aligns with Hawai‘i’s strict rabies-prevention rules. The Hawai‘i Department of Agriculture & Biosecurity Animal Quarantine Branch explains that Hawai‘i is rabies-free and that all dogs and cats—regardless of age or purpose—must comply with Hawai‘i’s dog and cat import requirements under Chapter 4-29 Hawaii Administrative Rules. Animals that meet pre- and post-arrival requirements may qualify for the 5 Day Or Less quarantine program (with a provision for direct release at Daniel K. Inouye International Airport after inspection); animals that do not meet those requirements may face quarantine of up to 120 days. Direct airport release fees and documentation timelines are published on the Hawai‘i Animal Quarantine Information page and change over time—verify them before any planned move into the state.

Puerto Rico

Southwest’s destination guidance flags that specific requirements may apply for Puerto Rico. The Puerto Rico Department of Agriculture (PRDA) State Regulations for Imports to Puerto Rico (updated November 11, 2024) state that dogs and cats do not need a PRDA import permit for interstate movement, but all dogs and cats entering Puerto Rico must be accompanied by an official health certificate / certificate of veterinary inspection signed by an accredited veterinarian in the state or territory of origin, valid for 30 days from inspection, stating the animal did not originate from a rabies-quarantined area. Dogs and cats over four months of age must be vaccinated against rabies within six months prior to shipment and carry a rabies vaccination certificate; external-parasite treatment within 72 hours prior to entry must be stated on the health certificate; and official individual identification (microchip or a collar with a metallic ID tag) is required.

International flights

Southwest Airlines’ Contract of Carriage states that no pets will be accepted on international itineraries. For trips that would leave the United States, the United States Department of Agriculture Animal and Plant Health Inspection Service (USDA APHIS) Pet Travel Process Overview explains that destination-country rules can require microchips, vaccinations, tests, and USDA-endorsed health certificates issued by a USDA-accredited veterinarian—and that airlines may impose additional requirements. Because Southwest does not accept pets on international itineraries, those USDA APHIS export steps apply when you use another carrier or route for the international leg.

Pet dog vs. trained service dog vs. emotional support animal

The U.S. Department of Transportation (DOT) final rule “Traveling by Air With Service Animals,” published in the Federal Register on December 10, 2020, defines a service animal 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, including a physical, sensory, psychiatric, intellectual, or other mental disability. Carriers are not required to recognize emotional support animals as service animals and may treat them as pets. Psychiatric service animals that are task-trained are treated like other service animals.

Southwest Airlines Co. announced on January 25, 2021, that effective March 1, 2021—consistent with the DOT rule—it would accept only trained service dogs and would no longer transport emotional support animals. Southwest’s Contract of Carriage mirrors that framework: trained service animals travel at no charge with a completed DOT Service Animal Air Transportation Form; emotional support animals, comfort animals, companionship animals, and service animals in training are not trained service animals for Contract of Carriage purposes. Southwest may accept a maximum of two trained service animals per qualified individual with a disability, and the animal must be harnessed, leashed, or otherwise tethered at all times in the airport and on the aircraft.

How to book and fly a pet 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 fully inside a carrier that fits under the seat.
2. Call Southwest to reserve the pet space. Pet reservations can only be booked by calling Southwest, and space is limited (including a contractual cap of up to six pet carriers per flight).
3. Check destination rules. Avoid mainland–Hawaii and any international itinerary for pets; for Puerto Rico, arrange the PRDA-required health certificate, rabies documentation, parasite treatment, and ID before travel.
4. Arrive at the airport ticket counter. Check the pet in, pay the pet fare with an accepted credit card, then proceed through security with the carrier.
5. Keep the dog inside the carrier at the gate, during boarding, and for the entire flight. Do not sit in an exit row.

Animal identity records vs. airline travel documents

Airline pet policies, USDA APHIS export health certificates, Hawai‘i quarantine paperwork, and European Union pet passports under official pet-travel schemes are government or carrier travel documents. They are not the same product as Animal Passport.

Animal Passport is a digital animal and livestock passport that uses muzzle biometrics—the nose print is unique like a fingerprint—captured by phone. The record can bind owner, breed, estimated age, body condition, and vaccination history. Age is estimated from a dental photograph with a confidence score, and body condition is scored 1–5 from a side-profile photo. In August 2025, the system was used in livestock flood rescue in Pakistan so farmers could reclaim animals when paper tags washed away. Those identity records can help owners keep vaccination and ownership history organized for personal or farm records, but they do not replace Southwest’s pet fare process, a DOT service-animal form, a USDA-endorsed certificate, or a government-issued travel document. For more field notes, see the Animal Passport blog.

Practical tips before you fly

• Book early by phone; pet space fills first-come, first-served and can be capped at six carriers per flight under Southwest’s Contract of Carriage.
• Practice carrier time at home so the dog can stand, turn, and settle without distress.
• Carry vaccination records even when Southwest does not list a domestic health-certificate requirement—destination or layover authorities may still ask.
• Plan relief-area stops; Southwest’s public pet guidance notes the airline will not hold a flight for a pet-relief break.
• If your dog is a trained service animal, complete the current DOT Service Animal Air Transportation Form after booking and bring it for ticket-counter or gate presentation as Southwest requires.

Rules, fees, and destination health requirements change. As of September 2026, verify Southwest Airlines’ Optional Travel Charges and Contract of Carriage, plus destination agency pages (Hawai‘i Animal Quarantine, PRDA, USDA APHIS), before you travel. This article is informational reporting by Animal Passport and is not veterinary or legal advice.