Southwest Pet Policy: Airport-to-Cabin Checklist

Southwest accepts small, vaccinated domestic cats and dogs in the cabin on domestic flights (Southwest Pet Policy, verified 18 August 2026). They must travel in an appropriate carrier and be at least eight weeks old (Southwest Pet Policy). Southwest does not transport pets in the cargo compartment (Southwest Pet Policy). Space is limited (Southwest Pet Policy). Southwest recommends reserving in advance by phone (Southwest Pet Policy). At the airport, pay the required Pet Fare at the ticket counter (Southwest airport guidance, verified 18 August 2026). Carry the pet through screening while the carrier is X-rayed (Southwest airport guidance). Then keep the whole pet inside the carrier through the gate, boarding, flight, and deplaning (Southwest airport guidance). Trained service dogs use a separate process (Southwest service dog policy, verified 18 August 2026). They require a completed U.S. DOT form (Southwest service dog policy).

Southwest rules verified 18 August 2026. This checklist uses Southwest's live pet and trained service dog wording. Recheck the official pages before travel. Southwest says Pet Fare pricing may change at any time (Southwest Pet Policy).

What does Southwest require for a dog to fly?

For the ordinary-pet path, the dog must be a small, vaccinated domestic dog (Southwest Pet Policy). It must be in an appropriate cabin carrier on a domestic flight (Southwest Pet Policy). The pet must be at least eight weeks old (Southwest Pet Policy). Southwest does not transport pets in the cargo compartment (Southwest Pet Policy). An Unaccompanied Minor cannot travel with a pet (Southwest Pet Policy).

Use these checkpoints in order:

1. Confirm the animal belongs on the pet path. Southwest's ordinary-pet wording covers small, vaccinated domestic cats and dogs (Southwest Pet Policy).
2. Confirm the flight belongs on the pet path. Southwest publishes this acceptance for domestic flights and notes that destination-specific policies apply (Southwest Pet Policy).
3. Reserve space. Southwest says space is limited and recommends making a reservation in advance by calling (Southwest Pet Policy).
4. Use an appropriate carrier. Each ticketed customer may bring one pet carrier, and it may hold up to two small cats or dogs of the same species (Southwest Pet Policy).
5. Keep the animal contained. The pet, including its head and tail, must stay inside the carrier in the gate area, during boarding and deplaning, and throughout the flight (Southwest Pet Policy).

Southwest says a pet may be denied transportation if the containment rules are not followed (Southwest Pet Policy). It also says a pet showing disruptive behavior may be denied boarding. Its examples include scratching, excessive whining or barking, and growling (Southwest airport guidance). Southwest also lists biting, jumping, lunging, and urinating or defecating in the cabin or gate area (Southwest airport guidance).

Which rule applies at each Southwest checkpoint?

Treat booking, airport payment, screening, gate containment, and onboard stowage as separate checks. The table follows Southwest's current division between its booking policy and airport guidance.

Scope check: This is Southwest's transport process, not a destination-entry checklist. For a trip with separate government paperwork, start with the USDA pet travel navigator. If the dog is leaving the United States, use the international health certificate guide to identify the separate document path.

How much is the pet fee on Southwest?

Southwest's current pet page says a Pet Fare is required (Southwest Pet Policy). It does not print a dollar amount in the policy wording checked for this guide. It sends customers to its Optional Travel Charges page for pricing (Southwest Pet Policy). It says that pricing may change at any time (Southwest Pet Policy).

The Pet Fare must be paid at the Southwest ticket counter using accepted credit cards (Southwest Pet Policy). If the reservation is canceled, Southwest says the Pet Fare is refundable (Southwest Pet Policy).

This guide does not repeat an amount from an old article, search result, or traveler report. Open Southwest's pricing link from the live pet page when you check the fare.

What size pet carrier fits under a Southwest seat?

The current Southwest policy says the carrier must be stowed under the seat (Southwest Pet Policy). It does not state measurements on that page. Southwest links from the policy to its acceptable-carrier guide (Southwest Pet Policy). Use that live link when choosing a carrier. Do not use dimensions from a story. Do not use dimensions from an older page.

The allowance rules that Southwest does publish on its airport page are:

• The carrier counts as a personal item or a carryon item (Southwest airport guidance).
• You may board with a pet carrier and a personal item, or with a pet carrier and a regular-size carryon bag (Southwest airport guidance).
• Each ticketed customer may bring one pet carrier (Southwest Pet Policy).
• One carrier may hold up to two small cats or dogs of the same species (Southwest Pet Policy).

For the wider airline-versus-government decision, use our airline pet policies guide. Southwest's live answer still controls this flight.

Does Southwest require proof of vaccination for pets?

Southwest describes accepted ordinary pets as vaccinated domestic cats and dogs (Southwest Pet Policy). The pet and airport pages checked for this guide do not say that a passenger must show a vaccine record. This does not promise that no document can apply to a destination.

Do not convert Southwest's word “vaccinated” into veterinary advice or a made-up certificate rule. Check the live Southwest destination-specific link for the itinerary. Check the destination authority separately when the route requires it. The USDA pet travel navigator helps separate domestic, export, and import paths.

What if your dog has to pee on a flight?

Southwest says the pet must remain secured inside the carrier for the entire flight (Southwest airport guidance). Its airport guidance says pet relief areas are available at every location Southwest serves, but the airline will not hold a flight while a customer takes a pet to one (Southwest airport guidance).

Southwest lists urinating or defecating in the cabin or gate area as disruptive behavior. It says a pet showing disruptive behavior may be denied boarding (Southwest airport guidance). The approved pages do not give a vet schedule or an onboard exception. This guide does not invent one.

Airport decision: Locate the airport's relief area as part of your own route plan, but do not assume Southwest will delay departure for a visit (Southwest airport guidance).

Are trained service dogs covered by the pet policy?

No. Southwest has a separate path for fully trained service dogs (Southwest service dog policy). These dogs are trained to do work or tasks for a qualified person with a disability (Southwest service dog policy). Dogs are the only trained service animals Southwest accepts (Southwest service dog policy). Service animals in training may qualify to travel as pets (Southwest service dog policy). The same is true for emotional support animals and therapy animals (Southwest service dog policy).

For the trained service dog path:

• Present a completed digital or printed U.S. DOT Service Animal Air Transportation form at the ticket counter or gate on the travel day (Southwest service dog policy).
• Date the form on or after the ticket purchase date (Southwest service dog policy).
• Do not substitute a vest, harness, ID card, or registration certificate for the form (Southwest service dog policy).
• Keep the dog harnessed, leashed, or otherwise tethered at the airport and onboard (Southwest service dog policy).
• Check in with a Southwest Customer Service Agent at the ticket or departure-gate counter and present the form (Southwest service dog policy).

Onboard, the trained service dog must sit at the customer's feet (Southwest service dog policy). It may sit in the customer's lap if no larger than a child under age two (Southwest service dog policy). The dog may not block an exit or exit path (Southwest service dog policy). It may not extend into the aisle, use a seat or tray table, or enter a nearby seat's space (Southwest service dog policy).

What are the final Southwest pet policy checks?

Use Southwest's own pages as the booking and airport gate, then keep destination rules separate. Before leaving:

• Recheck pet eligibility, domestic-flight wording, and age on the live pet page (Southwest Pet Policy).
• Call in advance because Southwest says pet space is limited (Southwest Pet Policy).
• Open Southwest's current pricing link instead of carrying forward an old fee (Southwest Pet Policy).
• Plan for counter payment, screening, gate containment, and under-seat stowage (Southwest airport guidance).
• Use the separate trained service dog page and DOT form when that path applies (Southwest service dog policy).

For a different carrier's flight-specific checks, use the American Airlines pet policy pre-flight checklist and then confirm the live itinerary with American.

Pet insurance does not change Southwest's acceptance, carrier, payment, or documentation rules. For a separate coverage decision, compare pet insurance and read the policy terms.

Frequently asked questions

Can an unvaccinated pet fly on Southwest?

Southwest's ordinary-pet policy welcomes small, vaccinated domestic cats and dogs in an appropriate cabin carrier on domestic flights (Southwest Pet Policy). The approved page does not publish an exception for an unvaccinated ordinary pet. This guide cannot confirm eligibility.

Can cats fly on Southwest?

Yes. Southwest accepts small, vaccinated domestic cats in an appropriate carrier in the cabin on domestic flights (Southwest Pet Policy). Its other policy conditions still apply (Southwest Pet Policy).

Does Southwest put pets in cargo?

No. Southwest states that no pets are transported in the cargo compartment (Southwest Pet Policy).

Can two pets share one carrier?

Southwest says one carrier may hold up to two small cats or dogs of the same species (Southwest Pet Policy). The whole pet must remain inside the carrier during the required travel stages (Southwest Pet Policy). This includes the head and tail (Southwest Pet Policy).

Does a service dog use the ordinary pet carrier rules?

Southwest gives fully trained service dogs a separate process (Southwest service dog policy). If a trained service dog uses a carrier, Southwest says that carrier must be under the seat in front of the customer for taxi, takeoff, and landing (Southwest service dog policy).

Written by the FG Team, the Furry Guardian editorial team, who keeps these border rules current.