FORT WORTH, Texas -- Seven puppies are dead after traveling aboard an American Airlines plane to O'Hare International Airport Tuesday, prompting an investigation by the carrier.
The puppies were among 14 that were traveling from Tulsa, Oklahoma to Chicago.
Flight 851 left Tulsa at 7:30 a.m. and arrived at O'Hare around 9 a.m. the airline confirmed.
Five of the young pups died on board and two died later on at a veterinarian's office.
Airline spokeswoman Mary Frances Fagan said Wednesday the shipper put 14 puppies aboard Flight 851, which was scheduled to leave Tulsa at 6:30 a.m. but was delayed an hour by storms in Chicago.
American said on its website it won't carry warm-blooded animals if the actual or forecast temperature is above 85 degrees.
As the plane sat on the tarmac in Tulsa, it was already 86 degrees before 7 a.m., according to the National Weather Service.
Fagan said cargo holds carrying animals are routinely kept between 50 and 70 degrees.
Baggage handlers taking the puppies to a kennel area at O'Hare Airport grew concerned because they looked lethargic.
Employees tried to cool down the dogs, and they were taken to a vet's office, but five died initially and two others died later, Fagan said.
Several of the puppies were headed to connecting flights.
Fagan declined to identify the shipper or say whether American had taken animals from the same shipper before and, if so, whether there had been problems with any previous flights.
"We don't disclose information about our shippers any more than we disclose information about our passengers," she said.
Last month, the U.S. Department of Transportation said short-faced dogs such as pugs and bulldogs accounted for about half of the dogs that died during U.S. flights in the last five years.
Veterinarians say those dogs are more likely to have breathing problems.
Officials said pet owners should:
-- Book animals during moderate weather, if possible, and book them on flights that have the least number of connections (none is preferable.)
-- Avoid holidays and weekends when airline baggage-handling staffing is typically at lower levels.
-- Have someone waiting at the destination airport to pick up the animal as soon as possible.
In addition, the USDA stipulates that no more than two puppies or kittens, eight weeks to six months of age, may be transported in the same enclosure aboard air carriers.
Despite concerns about the stress animals experience while being transported as live cargo, statistics show that air travel is the safest form of transportation for animals as well as people.
Some 144 animals, including 122 dogs, died while being transported via air in the last five years, according to data reported by the U.S. Department of Transportation.
Those are only the cases involving pets reported by the airlines to the government.
The tally does not include deaths involving animals shipped by commercial breeders or livestock.
The department last month released data showing that "short-faced'' dog breeds such as pugs and bulldogs represent about half of the canines that die while being transported on planes.
Continental Airlines reported 40 animal deaths during transport in 2009, the highest number among U.S. carriers.
American was second, with 28 deaths; followed in the top five by Delta Air Lines, 17 deaths; Alaska Airlines, 16; and United Airlines, 13 deaths, according to the U.S. DOT.
