"100 percent of our incidents over the last 16 months were as a result of preexisting causes or were self-inflicted," Thurston said in an e-mail about the deaths. "None were due to our handling of the animal."
Atlanta-based Delta Air Lines had three deaths and three lost animals (including Vivi, a whippet that ran away after attending the Westminster dog show last February in New York and was not found). "We strive to care for all the animals entrusted to us," said spokeswoman Gina Laughlin.
Continental expects to ship 110,000 pets as cargo and 55,000 in-cabin, Thurston said. United Airlines flies about 150,000 pets a year in cargo and in-cabin, spokesman Jeff Kovick said.
Tad Hutcheson of AirTran Airways said his company decided years ago to allow pets only in the cabin. "It's not good for the pet to fly in cargo," he said.
Veterinarian Mike Younker, president of the Georgia Veterinary Medical Association, said flying pets in the cabin is safe, but otherwise he advises people to leave pets at home with a sitter.
"If they stress easily, or they get stressed when you board them, then they probably won't fly well," he said.
Pet owners need to know their animals --- and share the responsibility, vets and industry spokesmen said. American Airlines' Smith said some owners fly sick or overweight pets. One pet died after its owner administered a human-grade tranquilizer before the flight.
Ray Harbour of Atlanta never flies with her Chinese crested dog, even in the cabin.
"I know it just wouldn't work for him, that he'd be crying and barking the whole time," said Harbour, who instead leaves Romeo, 7, with a neighbor.
But Barbara Whitford, who was boarding a flight from Atlanta to Chicago for Thanksgiving last week, said her tea cup Yorkshire terrier, Bogie, never makes a scene.
"Most people don't even know we're traveling with a dog," Whitford said.
Tracey Thompson, founder of PetFriendlyTravel.com, a Web site for people who travel with their pets, said she thinks traveling in cargo holds is too stressful.
"The truth is the number of injuries and deaths is pretty low, but that said, I would never, never put a pet of mine in the cargo hold of a plane," Thompson said. "As a pet owner, you have to know your pet's limitations and personality and ultimately do what's best for your pet and not what's best for you."
To look at all of the Airline Animal Incident Reports go to airconsumer.ost.dot.gov/reports.
Staff writer Bridget Gutierrez contributed to this article.
PET TRAVELS BY AIR OR CAR
* Before travel, always have a pet checked by vet and take shot records with you.
* Leave yourself plenty of time to check your pet in. If you're stressed, your pet will pick up on it.
* Book reservations early. Restrictions vary widely among airlines, flights and time of year. Check requirements ahead.
* Use bungee cords, ties or even duct tape to ensure a pet's kennel doesn't break open during transit.
* Book a nonstop flight, even if it costs more.
* When driving, keep pets in a carrier or a harness attached to a seat belt.
* Don't leave pets unattended in a car or hotel.
* Call hotels ahead to see if pets are allowed in rooms and if they have breed or size restrictions.
* If taking a pet to someone else's house, clear it with the host.
Sources: Susan Sims, publisher of Fido Friendly magazine; Dr. Melinda Merck; and Tracey Thompson, founder of PetFriendlyTravel.com
Last year the U.S. Department of Transportation started requiring airlines to file monthly reports on incidents involving pets.
Airline statistics show less risk to animals than groups estimated.
Twenty-one animals stowed in cargo areas of airplanes have died since the Transportation Department began requiring airlines in May to record the number of pets that die on flights.
As coldblooded animals readily adapt to temperature shifts, they make great passengers.