French Bulldogs, Pugs, Boston Terriers, Pekingese, Shih Tzus and similar dogs are called brachycephalic breeds. They are very cute, but they are breathing disasters waiting to happen. The nasal structures in brachycephalic breeds are compressed to create tortuous systems of air passages. Brachycephalic dogs have trouble breathing under the best circumstances. They have low tolerances for heat and stress. Obesity, which is rampant among many brachycephalic breeds (especially Pugs and Bulldogs), exacerbates these problems.
I have always suspected that brachycephalic dogs would be most likely to die in the stressful and often hot circumstances involved in air cargo travel. Here are quotes from the JAVMA article.
Brachycephalic dogs more likely than others to die during air transport
Since May 2005, U.S. airlines have had to file monthy reports with the DOT on incidents involving the death, injury, or loss of pets during transport as cargo.
In the past five years, airlines have reported 122 dog deaths . . . The DOT believes the number of dogs and other pets that die during transport as air cargo is an extremely small percentage of the total number of pets that airlines carry . . . about half the pet dogs that died during transport as air cargo in the past five years tbelonged to brachycephalic breeds such as English Bulldogs, Pugs, French Bulldogs, and American Staffordshire Terriers.”
It sounds like the study could use a good statistical working over. For instance, the DOT should be able to calculate the exact percentage of dogs that die during air transport; with the numbers available, it should be possible to calculate specific risk ratios for individual breeds.
But the take-home message is clear: brachycephalic dogs are at increased risk when traveling in the cargo hold.
What should a concerned owner do? If you have a cat or a small dog (regardless of whether it’s brachycephalic), fly with it in the main passenger cabin. Avoid travel during hot months, and especially avoid daytime connecting flights in places like Dallas and Atlanta where it’s steaming hot on the tarmac. Keep your pet’s weight appropriate. Habituate your pet to the crate that will be used for transport to reduce stress during travel. Consider taking a road trip instead of flying.
Some vets recommend tranquilizers for pets that will be traveling as cargo. Tranquilizing drugs have risks and benefits; you should discuss them thoroughly with your vet before using them. I generally recommend against them.