A woman carries her dog at Qingdao Long Distance Bus Station. Zhou Kun / For China Daily

It's not cheap to transport a pet internationally, and the fee usually depends on the animal's weight and distance of the flight.

Zhang charges about 2,000 yuan for an international shipment, not including airline fees and end-destination costs.

Some pets, however, suffer from taking a flight. To's cats hid when they got home and were traumatized for about three weeks.

Liu Lang, vice-president of the Beijing Small Animal Veterinary Association, says this is often par for the course and suggests pets are given sedatives before being shipped.

Zhang of HFDS adds owners have to sign a contract agreeing the airline cannot be held responsible if the pet is injured or dies while being shipped.

In August 2012, a woman surnamed Zhao shipped her two golden retrievers on China Southern Airlines. The flight case broke and after going missing for 30 hours, one of the dogs was found dead at Beijing's airport.

Zhao said the case broke because it was unloaded without due care and sued the airline. The suit is ongoing.

And there have been similar examples. In response, 81 animal protection organizations wrote an open letter to the Civil Aviation Administration of China in September, calling for an improvement of the management of live animal shipments and "civilized" loading and unloading of animals.

"Such accidents can't be avoided, but the risk rate is much lower than shipping by train or by bus. Dogs may run about if the flight case breaks when unloading is not done carefully," Zhang says.

"If the dog runs onto the runway, it must be shot to ensure the safety of flights. Some pets die of heatstroke in summer if the airplane postpones takeoff because of high temperatures in the luggage cabin."

xulin@chinadaily.com.cn