Where Do They Put Animals On A Plane?

The Quick Answer

Animals travel in one of three places on a plane: in the cabin under your seat, in the pressurized cargo hold beneath the passenger cabin, or through a dedicated cargo shipping service. Small pets fly in-cabin in an approved carrier. Larger animals go in the cargo hold, which is pressurized and temperature-controlled — it's not the horror show many people imagine. And for very large animals or special transport needs, airlines offer standalone cargo shipping.

In-Cabin: Under the Seat in Front of You

Small dogs, cats, and sometimes small birds or rabbits can fly in the passenger cabin. Your pet rides in a carrier that slides under the seat in front of you, essentially taking the place of your personal item.

Size and Weight Requirements

The carrier — with your pet inside — needs to fit under the seat. Every airline has slightly different maximum carrier dimensions:

• American Airlines: 18" x 11" x 11" — pet fee is $150 each way
• Delta: 18" x 11" x 11" recommended — pet fee is $95 each way for domestic
• United: 17.5" x 12" x 7.5" (hard-sided) or 18" x 11" x 11" (soft-sided) — pet fee is $150
• Southwest: 18.5" x 8.5" x 13.5" — pet fee is $125 each way
• JetBlue: 17" x 12.5" x 8.5" — pet fee is $125 each way
• Alaska Airlines: 17" x 11" x 9.5" — pet fee is $100 each way

Most airlines cap in-cabin pets at around 20 pounds including the carrier, though some airlines like Alaska and JetBlue have dropped specific weight limits and just require the carrier to fit under the seat.

What It's Like for Your Pet

Your pet stays in the carrier for the entire flight. No taking them out to sit on your lap — that's a firm rule. The carrier must remain closed and stowed under the seat during taxi, takeoff, and landing. Your pet can see out through the mesh sides of a soft carrier, and you can reach down to offer comfort.

It's essentially a very noisy, pressurized car ride from your pet's perspective. Most cats and dogs do fine, especially on shorter flights.

Cargo Hold: Below the Passenger Deck

Larger dogs and other animals that don't fit under a seat travel in the cargo hold. This is the area below the main passenger cabin, and it's the option that causes the most anxiety for pet owners. But here's what you need to know.

It's Pressurized and Temperature-Controlled

The cargo hold where animals travel is pressurized to the same level as the passenger cabin. Your dog is breathing the same air at the same pressure as you are upstairs. The myth that cargo holds are unpressurized death traps is exactly that — a myth.

Temperature is maintained between approximately 45°F and 75°F in the animal section of the cargo hold. Airlines have specific compartments designated for live animal transport that receive dedicated heating and cooling. The captain is informed when animals are aboard and can adjust hold temperatures from the cockpit.

What the Space Looks Like

The animal cargo section is a designated area within the lower cargo hold. It's dark (no windows), noisy from engine sounds, and filled with cargo containers and luggage. Your pet travels in an IATA-compliant hard-sided kennel that's secured to prevent shifting during the flight.

The kennel must be large enough for your pet to stand up, turn around, and lie down comfortably. It needs a water dish attached to the inside of the door, absorbent bedding, and clearly labeled "Live Animal" stickers with directional arrows.

The Real Risks

The biggest danger isn't the flight itself — it's ground handling. The periods when your pet is most vulnerable are:

• On the tarmac: Before loading and after unloading, kennels can sit on the ramp exposed to weather. On hot days, tarmac temperatures can exceed 120°F.
• In cargo facilities: Some holding areas lack climate control
• During transfers: Connecting flights mean more ground handling time

This is why airlines impose temperature embargoes. Most airlines won't transport pets in cargo when ground temperatures at any point along the route exceed 85°F or drop below 45°F. For snub-nosed (brachycephalic) breeds like bulldogs, pugs, and Persian cats, the heat cutoff is even lower — typically 75°F — because these breeds have compromised airways that make them especially vulnerable.

Which Airlines Offer Cargo Pet Transport?

Not all airlines still transport pets as checked baggage in cargo. The landscape has shifted significantly:

• American Airlines: Offers checked pet service (PetEmbark) on select routes
• United Airlines: PetSafe cargo program for larger animals
• Alaska Airlines: Accepts pets as checked baggage in the cargo hold
• Delta: Discontinued cargo pet transport for most routes — only accepts pets in cabin
• Southwest: Cabin only, no cargo pet transport
• JetBlue: Cabin only, no cargo option

Cargo Shipping: Dedicated Animal Transport

For very large dogs, multiple pets, or situations where checked baggage pet service isn't available, dedicated cargo shipping is the third option. Companies like United PetSafe, American Airlines Cargo, and independent pet transport services handle this.

With cargo shipping, your pet travels as freight on a scheduled flight. You don't need to be on the same plane. The animal is handled by cargo specialists, and the service typically includes:

• Pickup and delivery to/from the cargo facility
• Climate-controlled holding areas
• Priority loading to minimize tarmac exposure
• Tracking updates

Costs vary widely — expect $200 to $1,000+ depending on the animal's size, route, and service level.

Emotional Support and Service Animals

Service animals — specifically trained dogs that perform tasks for people with disabilities — fly in the cabin at no charge and don't need to be in a carrier. They sit at your feet or on your lap. Airlines can require documentation, including DOT disability service animal forms completed at least 48 hours before the flight.

Emotional support animals (ESAs) no longer receive special treatment from U.S. airlines. After rule changes, ESAs are treated like regular pets — they need to meet the same carrier size requirements and pay the same pet fees. The days of bringing an untrained ESA on board for free are over.

Exotic and Unusual Animals

What about animals that aren't dogs or cats? It depends heavily on the airline:

• Small birds: Some airlines allow them in-cabin in covered carriers (United, American)
• Rabbits: A few airlines accept them in-cabin (Frontier, for example)
• Reptiles, rodents, spiders, ferrets: Almost universally banned from both cabin and cargo on commercial airlines
• Horses, livestock, large exotics: Require specialized charter cargo services

How to Prepare Your Pet for Flying

• Visit your vet: Get a health certificate issued within 10 days of travel. Most airlines require this for cargo travel, and some require it for cabin too.
• Acclimate to the carrier: Start weeks before the trip. Leave the carrier open at home with treats inside so your pet associates it with comfort, not stress.
• Book early: Airlines limit the number of pets per flight — usually 2-4 in cabin. Call the airline to reserve a pet spot; you often can't add a pet online.
• Choose direct flights: Fewer connections mean less ground handling time and lower risk.
• Skip the sedatives: Veterinary associations and airlines generally advise against sedating pets for flights. Sedation can affect breathing and temperature regulation at altitude.

The Bottom Line

Small pets ride under your seat in an approved carrier. Larger animals travel in the pressurized, temperature-controlled cargo hold in hard-sided kennels. The cargo hold is not the terrifying place people imagine — it's pressurized and climate-controlled — but the ground handling phases are where real risks exist. Choose direct flights, follow airline requirements, and check temperature embargoes before booking your pet's trip.