Baby panda cause of death: Underdeveloped lungs, liver disease

The National Zoo’s six-day old baby panda died from underdeveloped lungs and liver disease, zoo officials said Thursday.{ }

The zoo disclosed the cause of death Thursday morning at a news conference.

Suzan Murray,{ }the institute's chief veterinarian, said the cub's cause of death was liver necrosis, or the death of liver cells.

Murray said at a news conference the cub's lungs were also underdeveloped and likely didn't provide enough oxygen to the liver. The cub's underdeveloped lungs may have been caused by being born prematurely, Murray said. Zoo scientists are trying to learn more about how common the liver and lung defects are in newborn pandas that don't survive.

The cub, believed to be female, was born Sept. 16. Zoo officials and panda fans around the world were devastated by its death less than a week later. The birth was a surprise because it hadn't been clear whether the mother, 14-year-old Mei Xiang, was still fertile.

Panda cubs are born hairless and helpless, about the size of a stick of butter. The mortality rate for females born in captivity is 20 percent in the first year.

A preliminary necropsy revealed that the cub had liver abnormalities and fluid in its abdomen. Zoo officials say they are not sure why the panda cub suffered those abnormalities, but they say there was no trauma to the body.

Visitors like Bob Clarke from South Carolina hope the zoo tries again for another pregnancy in the near future.

"It's a beautiful animal,” says Clarke.

Don Moore, the zoo's associate director for animal sciences, said panda mother Mei Xiang has been showing less mothering behavior and has stopped cradling a toy in recent days.

In addition, after spending nearly four weeks in her den, she has stopped staying inside and is sleeping out in the panda yard. As a result, zoo keepers on Wednesday cleared out the nest she had built.

The zoo has a five-year agreement with China to keep its two pandas, Mei Xiang and Tian Tain, through 2015. Murray will travel to China this month as the zoo begins planning for the future.

They will discuss whether to keep both pandas in Washington or to swap one or both out for the next breeding season. A decision should be made in November, Moore said.

The Associated Press contributed to this story.