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Kennel requirements

United is committed to providing safe and secure travel for all of our passengers, including animals. For this reason, pets traveling as part of our PetSafe program must use an approved kennel that complies with U.S. Department of Agriculture (USDA) and International Air Transport Association (IATA) regulations. Review the kennel requirements below to help keep your pet safe and comfortable during air travel.

All kennels must follow the requirements below:

This kennel is the wrong size for your dog.

This kennel is the correct size for your dog.

  • The kennel must be constructed of rigid plastic, wood or metal. The roof must be solid with no doors or ventilation openings.
  • The kennel needs to have ventilation on three sides for travel within the 50 United States and Puerto Rico. The kennel must have ventilation on four sides for travel to and from all other destinations and for short-nosed dogs traveling to any destination.
  • The kennel must be large enough for your pet to freely sit and stand with its head erect, turn around and lie down in a normal position.
  • Your pet's head or ear tips, whichever is higher, cannot touch the top of the crate. If your pet’s kennel does not provide enough room for your pet to stand and sit, without the head touching the top of the container, you will need to purchase a larger kennel before your pet can fly. Approved kennels may be available for sale at some United Cargo locations, in addition to many pet supply stores.
  • United requires an additional three inches of height clearance when transporting your pet to and from any destination outside the U.S. and Puerto Rico. Short-nosed dogs require a kennel one size larger.
  • The kennel door must be made of metal. Plastic and Fiberglas™ doors, including side plastic latches, are prohibited because they are not strong enough to protect animals during normal handling.
  • All kennel hardware must be secure and in good working condition. A metal nut and bolt must be secured in each hole that is in place to connect the top and bottom of the kennel. Please note that it’s common for kennels to have nuts and bolts that are metal and covered with a plastic coating on the outside, and those are acceptable.
  • Snap-sided kennels or kennels with plastic side latches will not be accepted, unless you have drilled additional holes and added metal nuts and bolts to secure the kennel.
  • Kennels using twist locks to secure the top and bottom halves of the kennel will not be accepted.
  • Two dishes (one for food and one for water) must be attached to the inside of the kennel but also be accessible from the outside of the kennel so they can be filled from outside the kennel without opening the door.
  • The door must close securely. In accordance with federal regulations, animals must be accessible in the event of an emergency.
  • Regulations require that any wheels must be locked or otherwise rendered inoperable. Kennel wheels must be either removed or taped to prevent the kennel from rolling in transit.
  • The floor must be solid and leak-proof and contain absorbent material, such as shredded black-and-white printed newspaper.
  • Each kennel should contain no more than one adult dog or cat, or no more than two puppies or kittens younger than six months, of comparable size, and weighing less than 20 pounds (9 kg) each.
  • A single kennel cannot contain both dogs and cats (or puppies and kittens).

Items prohibited in kennels:

  • Toys
  • Medication, including over-the-counter or prescription (United does not administer medications.)
  • Thick blankets, bedding or similar items
  • Straw, hay or wood shavings are prohibited for international travel

Prohibited kennels:

  • Kennels with door openings on top
  • Kennels made entirely of cardboard, mesh (welded or wire), wicker or collapsible materials
  • Snap-sided kennels, kennels with plastic side latches or kennels with twist locks that are not secured by metal nuts and bolts

Required labeling

Label the top of your pet's kennel with your pet's name as well as the names, addresses and telephone numbers of the customers who will be dropping off and picking up the animal. Federal regulations require that each kennel is labeled to safeguard your pet. When you drop off your pet, United will provide the required labels to adhere to the kennel. The labels include:

  • The words "LIVE ANIMAL" will be adhered to the top and at least one side of the kennel in 1-inch (2.5-cm) letters.
  • Orientation labels that indicate the top of the kennel with arrows or "This End Up" markings will be adhered to at least two sides of the kennel.
  • Additional information and requirements can be found on the Required Labeling page.

Standard kennels types

The kennel types below are accepted on most United aircraft and are available for purchase at some of our cargo facilities.

Kennel type(#) Kennel size (in.) Estimated kennel weight (lb.) Kennel price Aircraft type acceptance
100 21 L x 16 W x 15 H 7 $75 All United aircraft Footnote
200 27 L x 20 W x 19 H 13 $90 All United aircraft Footnote
300 32 L x 22 W x 23 H 18 $125 All United aircraft Footnote
400 36 L x 24 W x 26 H 24 $145

All United aircraft Footnote
500 40 L x 27 W x 30 H 32 $160 All United aircraft Footnote
700 48 L x 32 W x 35 H 51 $250 All United aircraft Footnote , except Boeing 737

* Kennel acceptance guidelines noted above apply to United aircraft. Limitations may apply for travel on United Express® flights. The #400 series is the largest kennel size accepted on United Express aircraft, and not all United Express aircraft are able to accommodate pet kennels. Please call United PetSafe at 1-800-575-3335 to verify availability. Return to reference

Super-sized kennels
United can transport dogs in "giant" crates or kennels (#700 series) that do not exceed 48 in. long x 32 in. wide x 35 in. high (122 cm x 81 cm x 89 cm) on most Boeing aircraft. See the standard kennel types chart above for specific aircraft restrictions.

Reinforced crates
Select dog breeds as mentioned on the Pet Restrictions page require a reinforced crate. IATA Container Requirement #82 states that the container or crate must be constructed of wood, metal, synthetic materials, weld mesh or wire mesh. Additional design principles regarding frame, sides, floor, roof and doors also apply. No portion of the crate can be plastic. The crate door must be made of heavy wire mesh, metal or reinforced wood and should have a secure means of fastening that cannot be opened accidentally. The crate must also have substantial ventilation. For travel within the 50 United States and Puerto Rico, the crate must have ventilation on three sides. For travel to and from all other destinations and for short-nosed dogs traveling to any destination, the crate must have ventilation on four sides.

How to measure your pet

Kennel sizing chart for dogs and cats

A = Length of animal from nose to root of tail

B = Height from ground to elbow joint

C = Width across shoulders

D = Height of animal in a natural standing position from the top of the head or the ear tip, whichever is higher. Note: your pet's head or ear tips, whichever is higher, must not touch the top of the crate.

How to determine kennel size

For travel within the 50 United States and Puerto Rico:

Length = A + ½B
Width = C x 2
Height = D

For travel to and from all other destinations and for short-nosed dogs:

Length = A + B
Width = C + 1" (3 cm) x 2
Height = D + 3" (7 cm)

Acclimating your pet to its kennel

One of the most important steps you can take to ease the stress of travel for your pet is to make sure it becomes familiar with its kennel. Purchase the kennel as far in advance as possible. Veterinarians recommend leaving the kennel door open in the house with treats or a familiar object inside so that your pet may spend time near the kennel and perhaps venture inside on its own. Since it is important that your pet is as relaxed as possible during the flight, familiarization with the kennel is essential.