I just took another look at the site I mentioned and found there's some REALLY specific info, such as:

"Certain breeds including Boston Terrier, Bulldog, Boxer, Chow Chow, Lhasa Apso, Pekinese, Pug, and ShihTzu dogs, as well as Himalayan and Persian cats should not be transported by air as these breeds are more susceptible to breathing difficulties caused by the thin air at altitude."

and:

"The USDA prohibits the shipment of animals where temperatures at either the origin or destination are below 45 degrees or above 85 degrees. Many airlines have further temperature-related restrictions.'

and:

"Inquire as to the aircraft type planned for the route. McDonnell Douglas aircraft, including the MD80, DC9, and the DC10 will not accommodate 500-size crates. These crates should fit on Boeing aircraft, including the 727, 737, 747, 757, 767, and 777."

I hope this helps!