It's always best to keep your pet with you in the cabin, rather than checking your pet into the cargo hold. In fact, The American Society for the Prevention of Cruelty to Animals and the Humane Society have both released statements about the dangers of checking animals as cargo. Temperatures are unstable and many airlines have restrictions on pet travel at certain temperatures.
Checking your dog opens your trip up to a variety of problems. It's possible for pets to get lost, for carriers to topple over and for animals to get loose. At the very least, your animal might be frightened by the noise and conditions of a plane's cargo area. For an especially long flight, the fact that you can't feed, water or take your dog to the bathroom can be a problem.
Most of the major airlines allow you to carry one dog less than 20 lbs. in an approved carrier as your carry-on item. You'll need to make a reservation for your dog if you plan to take her on board with you, and your carrier must fit on the floor in front of your feet.
If you absolutely must check your dog into the cargo area with the rest of your luggage, the Unites States Department of Agriculture has set forth very specific regulations for approved carriers. The carrier must not allow any part of the animal, especially the hands and feet, to protrude. The animal must demonstrate that it can stand up, turn around and lay down comfortably in the carrier. The bottom must be leak-proof and lined with a towel or blanket.
You must purchase a carrier that has sufficient ventilation. It must have 14 percent open space at the walls and top with 33 percent of that space located on the top half of the carrier. You must label the carrier "live animal" and also use arrows on the crate to indicate which direction the cargo loaders should place it.
Your crate should contain a food bowl and a water bowl. You may be asked to verify that you've fed your dogs prior to boarding. Remove leashes and muzzles before placing the dog into the carrier. Add a label that contains your name and contact information and the contact information of someone who lives in your destination city.
Most airlines require that you make a reservation and pay a fee to take your animal on board. When you purchase your ticket, find out the proper process for making a pet reservation. Make a follow-up call two weeks and one week before your flight to confirm your pet's reservation. Call ahead the day before your flight to make sure pet restrictions haven't been placed on your flight due to extreme temperatures.
Order a health certificate from your vet. Some airlines require them, and they're needed for all international flights. You cannot take a dog on board who is sick, violent or less than 8 weeks old. Avoid giving your dog sedatives or tranquilizers because this can disrupt their natural sense of balance.
Arrive at the airport early enough to check your dog in personally. You cannot use curbside service for an animal. Your pet's carrier will be subject to search, so you must be able to remove your dog from the carrier if asked.