Check here to see airline's standard carry-on dog carrier sizes and for links to official pet travel by air information.

• Note that many airlines no longer accept snub-nosed or pug-nosed dogs and cats as checked baggage.
• Typically, airlines require pet health certificates that are no older than 10 days. Some countries require even less - check beforehand.
• If you are traveling with a Service Dog, check with the airline for special rules.

IATA Pet Travel Advice
Excellent reference for pet travel advice. The International Air Transport Association (IATA) is the trade association of airlines. Specific IATA Pet Travel Tips

USDA Traveling with your Pet
Rules and regulations for pet import and export.

U.S. Department of State Pets and International Travel PoliciesFor U.S. Government employees and family members of all foreign affairs agencies assigned to diplomatic posts abroad.

American Airlines
Pet Carrier Guidelines for Cabin Pets:
In cabin pet carriers: 19"L x 13"W x 9"H.
Soft-sided pet carriers such as Sherpa bags may exceed these dimensions slightly because they are collapsible. Animals must be able to stand up, turn around and lie down in a natural position in the kennel. Soft-sided pet carriers are accepted as long as they are constructed of water-repellent, padded nylon with mesh ventilation on two or more sides.

(excerpt from AA 05/2013)

United Airlines - Travel for Animals
In-cabin pet kennels:
Hard-sided kennels: 17.5"L x 12"W x 7.5"H (44 cm x 30 cm x 19 cm).
Soft-sided kennels: 18"L x 11"W x 11"H (46 cm x 28 cm x 28 cm).
Call United PetSafe Desk at 1-800-575-3335 or 1-832-235-1541.

(excerpt from UA 05/2013)

AirTran Airlines
Small, domesticated cats and dogs that will fit in an approved carrier under the seat are accepted for travel. Pets will not be allowed for flights that include a Southwest Airlines segment.

• The pet kennel is limited to maximum dimensions of 8.5"H x 17"L x 12"W
  
• The carrier must be leak proof and ventilated on at least two sides.
  
• There is no weight restriction on pets.
  
• The pet must remain in the carrier and under the seat for the duration of the flight.
  

(excerpt from ATA 05/2013)

Delta Pet Travel & Restrictions - Kennel Requirements
Kennel sizes are based upon dog size and Delta aircraft and whether carry-on, checked baggage or cargo.

To transport your pet in cabin either soft- or hard-sided kennels must be leak-proof and ventilated on at least two sides. Kennels are not sold at Delta Ticket Counters, but are available at most pet supply stores. Carry-on Information

To transport your pet as checked baggage or cargo, you must use an approved shipping kennel, and it must ship in accordance with the U.S. Department of Agriculture (USDA) guidelines. The kennel must provide enough room for your pet to stand and sit erect — without the head touching the top of the container — and to turn around and lie down in a natural position. Shipping Pets In Cargo

(excerpt from Delta 05/2013)

Southwest Airlines
Soft-sided and hard-sided carriers specifically designed as pet carriers are acceptable. The carriers must be leak-proof and well ventilated.The under-seat dimensions are as follows:

• Window Seat: 19"L x 14"W x 8.25"H
• Middle Seat: 19"L x 19"W x 8.25"H
• Aisle Seat: 19"L x 14"W x 8.25"H

(from SWA 5/2013)

U.S. Airways - Pets

• Hard-sided carriers: 17"L x 16"W x 8"H (43 cm x 40 cm x 20 cm)
• Soft-sided carriers: 17"L x 16"W x 10"H (43 cm x 40 cm x 25 cm)
• On US Airways Express flights: 15"L x 17"W x 8"H (38 cm x 43 cm x 20 cm)
• On CRJ aircraft: 16"L x 17"W x 8"H (40 cm x 43 cm x 20 cm)
• On DH3 and DH8 aircraft: 15"L x 16"W x 10"H (38 cm x 40 cm x 25 cm)

1. Carriers must be leak-proof and escape-proof.
2. Carriers must be ventilated on at least 2 sides, but not allow any part of the animal to protrude outside of the container.
3. Carriers must provide room for the animal to stand up and turn around.
4. Carriers can be made of metal, wood or hard plastic/composite. Exceptions are made for soft-sided containers made specifically for pet carriage.

(excerpt from USA 5/2013)

Lufthansa Animals
You may take a dog or cat into the cabin, if the weight of the animal (including carrier) does not exceed 17 pounds (8 kilograms).
Carrier: 21" x 15" x 9" (55 cm x 40 cm x 23 cm)

(from LA 05/2013)