I do not believe that it is safe to fly animals. The only condition I would ever consider flying a dog in would be if they were small enough to ride in a carrier under my seat and the airline allowed them to travel with me under the seat (some airlines do allow this).
I would never let my dog on an airline that flew them as cargo. Cargo holds are not temperature controlled, recieve no oxygen during the flight, and are not monitored by crew. A frightening number of pets are injured or killed during flights.
If you want to read a proffesional article about pets on flights, go to http://www.sfspca.org/advocacy/pdf/pdf_airplanes/final_report.pdf It is a long read, but even skimming the beggining will shock you.
As a former Flight Attendant, and having flown NUMEROUS dogs by air over the years, I have to disagree with you on several important points.
1) the Cargo area is ABSOLUTELY climate controlled. It gets the same air you do in the passenger compartment. The ENTIRE aircraft is pressurized for comfort and safety at altitutude. The cabin floor will not maintiain pressurization
. ALL cargo bins are DEFINITELY climate controlled. The ONLY exception is in a pressurization emergency in certain aircraft. The rear cargo bin on certain aircraft is called the "dead dog bin" because IF there is an emergency loss of pressure, that bin will NOT be climate controlled. Animals are not placed for shipment in these cargo bins.
2) the real enemy when shipping dogs are hidden health issues (heart or breathing issues), and heat. Dogs who are crate trained and comfortable in their crates, who are not shipped in hot weather, generally ship just fine. I do not ship dogs when the outside air temp is going to be above 75 degrees on either end of the flight. Heat kills dogs during shipping before or after takeoff and landing, when the cargo area is NOT cooled adequately.
I also take special care in making sure crates do not open during shipping. I am generally shipping large dogs, so I put cargo straps around the crate, so it looks like a package with ribbon on it. These keep the crate from accidentally ( or purposefully ) opening.
I put a BIG SIGN on the top of the crate that says something like:
My name is ********. This is my first flight, and I might be scared. (I put this even if the dog has flown before). Please speak kindly to me, and handle my crate gently. I am heat sensitive, and I appreciate being in the shade. Please do not put my crate on any conveyer belts.
I have shipped at least 10 times and never had any issue, but I'm careful.
If your breeder is also careful, and if the pup is used to a crate, you should have no issues.
I would caution that it is ALWAYS dangerous to ship short faced breeds such as bulldogs, pugs, bostons etc, and these dogs should fly inside the cabin with their owners.