Dog Carriers for Travel: How to Choose the Right Carrier for Plane, Train and Car

Dog carriers for travel are enclosures that keep a dog contained, ventilated and secured while it moves by plane, train or car, and the right one depends on the mode of transport. As of September 2026, Delta and American Airlines recommend a soft-sided cabin carrier of about 18 × 11 × 11 inches that fits under the seat. Amtrak caps carriers at 19 × 14 × 10.5 inches and 20 lb combined. Cargo crates follow International Air Transport Association (IATA) Container Requirement 1, and car carriers should be strapped down and crash-tested.

This guide compares dog carriers by trip type, using airline, rail and standards-body pages we opened in September 2026. It is written by the Animal Passport editorial team, which covers animal identity and movement. It is not veterinary or legal advice. Carrier rules change often, so always check the current policy of your carrier before you travel.

What is a dog travel carrier?

A dog travel carrier is a portable, closed container, either soft-sided (fabric and mesh) or hard-sided (plastic, metal or wood), that holds a dog safely during transport. Airlines, railways and standards bodies judge a carrier on four things: its outside dimensions, whether the dog has enough room inside, ventilation, and whether it is leak-proof and escape-proof.

People often use the words carrier, kennel and crate interchangeably. In practice, a carrier usually means a small bag or box that you hand-carry and stow under a seat. A crate or kennel is a larger, rigid box for cargo holds or vehicle cargo areas.

Dog carrier requirements by travel mode (comparison table)

The table below summarizes limits published on official pages as of September 2026. Always confirm against your own booking, because under-seat space varies by aircraft and route.

Airline cabin carriers: under-seat size rules

For small dogs flying in the cabin, the binding limit is the space under the seat in front of you. Delta Air Lines says the maximum in-cabin kennel dimensions are set by the aircraft, and it recommends a soft-sided kennel of 18 × 11 × 11 inches because that fits most aircraft types (Delta Air Lines, 2026). Delta also requires that the dog can move around without touching or sticking out of the sides, and that the soft-sided kennel is leak-proof, with ventilation on three sides for domestic flights and four sides for international flights.

American Airlines publishes the same 18 × 11 × 11-inch soft-sided figure, plus separate hard-sided limits: 19 × 13 × 9 inches on American mainline flights and 16 × 12 × 8 inches on American Eagle regional flights (American Airlines, 2026). American notes that non-collapsible kennels cannot exceed the under-seat dimensions of any aircraft on your journey, which is why a carrier that fits one leg of a trip can fail on a regional connection.

Cabin pet fees and limits in 2026

Delta charges $150 USD/CAD each way for in-cabin pets within the U.S., Canada, Puerto Rico and the U.S. Virgin Islands on tickets issued on or after April 8, 2025, and $200 on many international routes (Delta Air Lines, 2026). American Airlines lists a $150 carry-on pet fee per kennel within and between the U.S., Canada, Mexico, Central America and the Caribbean (American Airlines, 2026). Both airlines limit the number of pets per flight, so book your dog's spot early. Delta, for example, allows up to four pets in Delta Comfort and Delta Main and none in Delta One or Delta Premium.

Age and destination rules that affect your carrier

Delta requires pets to be at least 8 weeks old for domestic travel, and dogs entering the United States from another country must be at least 6 months old (Delta Air Lines, 2026). Delta does not allow in-cabin pets to or from several destinations, including the United Kingdom, Australia, New Zealand and Hawaii. If your route is on that list, a cabin carrier will not help, whatever its size.

For a deeper look at under-seat measurements, see our airline carrier size guide. It was written for cats, but the same airline limits apply to small dogs.

Cargo and checked crates: the IATA CR1 standard

Larger dogs that cannot fit under a seat usually fly as cargo or checked baggage in a rigid crate. The IATA Live Animals Regulations, Container Requirement 1 (CR1), Edition 52 (January 2026), cover domestic dogs and cats. The rules say every opening must be nose- and paw-proof, with openings no larger than 25 × 25 mm for dogs, and that any wheels must be removed or made inoperable (IATA, 2026). IATA's container guidance also requires ventilation equal to at least 16% of the total surface of the four sides, with ventilation on all four sides.

IATA states in CR1 that it "does not certify, approve, endorse, or sell any particular pet container manufacturer, brand, make, or model." In other words, an "IATA approved" label on a crate is marketing, not certification. Check the crate against the written standard and against your airline's own rules.

Some airlines also have their own variations on top of CR1. For example, IATA's 2026 operator-variations addendum lists airlines that require reinforced wood or metal CR82 containers for certain dog breeds. If your dog is a large or restricted breed, ask the airline which container requirement applies before you buy a crate.

How to size a dog crate with the IATA formula

IATA's Traveler's Pet Corner gives a formula for minimum internal crate dimensions (IATA, 2026). Measure your dog standing:

1. A: length from the tip of the nose to the base of the tail.
2. B: height from the ground to the elbow joint.
3. C: width across the shoulders or widest point.
4. D: standing height from the floor to the top of the head or ear tip, whichever is higher.
5. Calculate: length = A + ½B; width = C × 2; height = D plus bedding.
6. Add 10% for snub-nosed breeds such as pugs, boxers and bulldogs.

IATA also advises against transporting snub-nosed dogs in hot weather, because they have difficulty maintaining a normal body temperature.

Checked pets are restricted on some airlines

As of September 2026, American Airlines accepts checked pets at the ticket counter only for active-duty U.S. Military and U.S. State Department Foreign Service personnel on official orders, with a maximum combined weight of 100 lb (45 kg). Other dogs too large for the cabin must travel through American Airlines Cargo (American Airlines, 2026). Policies differ by airline, so a crate purchase should follow, not precede, confirmation of how your dog will fly.

Train travel: Amtrak dog carrier rules

Amtrak allows dogs and cats in carriers for a fee on most routes, but the limits are strict. According to Amtrak (2026), the pet and carrier together may weigh no more than 20 lb, and the carrier may be no larger than 19 inches long, 14 inches wide and 10.5 inches high. The carrier may be hard- or soft-sided but must be leak-proof and well ventilated. Trips are limited to seven hours total, including transfers.

Amtrak also requires the pet to sit and lie down without touching the sides of the carrier, and the carrier counts as one carry-on bag. On board, you place it under your own seat, not the seat in front, except on Amtrak Cascades. Pets are allowed in Coach and Acela Business Class, but not in Acela First Class or food service cars.

Car travel: secured and crash-tested dog carriers

In a car, the risk is not fitting under a seat but what happens in a sudden stop. The Center for Pet Safety (CPS), a 501(c)(3) nonprofit, runs a voluntary certification program in which manufacturers agree to meet independently developed safety standards, monitor quality control and commit to truth in marketing (Center for Pet Safety, 2026). CPS says it does not accept funding from pet product manufacturers.

CPS keeps a public list of certified carriers and kennels, which changes as products are tested. Practical rules for car travel:

• Secure the carrier or crate with the connection method it was tested with. A loose carrier can become a projectile.
• Check the maximum dog weight the product was rated for, not just whether the dog fits inside.
• Treat "crash tested" claims with caution unless the product appears on the CPS Certified list.
• Never leave a dog in a parked car in its carrier. Ventilation that works while driving may not work in a stationary, hot vehicle.

Soft-sided vs hard-sided dog carriers

Soft-sided carriers flex slightly under tight airline seats, which is why Delta and American both recommend them for cabin travel. American Airlines adds that a soft carrier must still fit under the seat without excessive collapsing, and a bag squeezed flat can block its own mesh ventilation. Hard-sided carriers protect better against crushing and are required for cargo, but their inches cannot compress. American Airlines therefore lists smaller hard-sided cabin limits for its regional jets.

• Choose soft-sided for small dogs flying in the cabin or riding Amtrak within the size limit.
• Choose hard-sided (IATA CR1) for cargo, checked travel and most dogs over carry-on size.
• Choose a crash-tested, strapped-in carrier or crate for road trips.

How to prepare your dog for a travel carrier

1. Confirm the mode and route first. Check whether your dog can fly in the cabin, must go as cargo, or cannot travel on that route at all.
2. Measure the dog, then the carrier. Use the IATA formula for internal space and measure the carrier's exterior, including pockets and handles.
3. Crate-train weeks in advance. IATA recommends buying the container early and getting the animal used to being confined in it, because familiarity reduces stress.
4. Do not rely on sedation. IATA discourages sedatives and tranquilizers for pets in transit, a view it says the American Veterinary Medical Association endorses. Any medication should be given only under veterinary direction.
5. Feed lightly and walk your dog. IATA advises reducing food the day before while still giving water, and walking the dog before leaving for the airport and again before check-in.
6. Label and identify. IATA recommends a microchip plus two collar tags: a permanent ID with your home details and a temporary travel ID with a contact number at your destination.
7. Reconfirm. IATA suggests reconfirming the pet booking at least 48 hours before departure. Delta asks you to have the kennel's length, width and height ready when you book.

Carriers do not replace pet travel documents

A correctly sized carrier satisfies stowage and welfare rules, not import law. The United States Department of Agriculture Animal and Plant Health Inspection Service (USDA APHIS) advises anyone taking a pet from the United States to another country to contact a USDA-accredited veterinarian as soon as they decide to travel. The vet helps with destination entry requirements and any USDA-endorsed health certificate (USDA APHIS, 2026). APHIS also notes that the U.S. Centers for Disease Control and Prevention (CDC) is the primary authority for dogs entering or returning to the United States. Delta's 2026 pet page adds that dogs entering the U.S. must be microchipped, at least 6 months old and accompanied by a completed CDC Dog Import Form receipt.

Official schemes such as the EU pet passport are government travel documents, and they are separate from carrier rules and from any private product.

How Animal Passport differs from pet travel documents

Animal Passport is a digital animal and livestock passport built on muzzle biometrics. An animal's nose print is unique, like a fingerprint, and is captured with a phone. The record links the owner, breed, estimated age, body condition and vaccination history. Age can be 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 after paper tags washed away.

Animal Passport is not an airline pet document, an EU pet passport, a CDC or USDA form, or a government-issued travel credential. It does not replace a microchip, health certificate or airline booking. To learn more about biometric animal identity, read the Animal Passport blog.

Bottom line

The best dog carrier for travel is the one that fits both your dog and your trip. For cabin flights, that usually means a ventilated, leak-proof soft carrier around 18 × 11 × 11 inches. For Amtrak, it means 19 × 14 × 10.5 inches and 20 lb or less. For cargo, you need an IATA CR1 crate sized by formula, and for the car, a secured, independently crash-tested carrier. Confirm the current rules with your carrier before every trip, because fees and limits change from year to year.