Giant pandas have a low rate of CDV infection. But once a giant panda is infected, it is difficult to detect early and the fatality rate is high, he said.

Currently, it is extremely difficult to cure the disease, and there have so far been no cases of successful treatment of the disease in giant pandas.

The CDV epidemic in the Shaanxi center has alerted other giant panda breeding centers in China to strengthen preventive measures.

"Some programs that involve close contact between giant pandas and the public have been suspended," said an official with the Chengdu Research Base of Giant Panda Breeding in southwest China's Sichuan Province, a major habitat for the endangered species.

The Chengdu base has also strengthened disinfection and control of tourists and staff to ensure the safety of the species, said the official.

In addition, the base has started to capture stray dogs and cats and conduct thorough checks on fences, ditches and sewage channels to prevent stray animals from entering the park area.

Giant pandas are one of the world's most endangered species. About 1,600 of the animals live in the wild, mostly in the mountains of Sichuan, while nearly 400 live in captivity.

The cause of the giant panda epidemic in Shaanxi is unclear.

"CDV infection in giant pandas may be caused by domestic or stray animals," said Jin Yipeng, a veterinary expert at China Agricultural University.

Nearly 30 domestic leading experts have joined the treatment efforts for CDV-infected giant pandas in Shaanxi, according to Zhang Hemin,director of the China Conservation and Research Center for the Giant Panda.

"To avoid an outbreak of highly contagious diseases among giant pandas, it is urgent to strengthen research on monitoring, prevention and treatment for identified and unidentified diseases in giant pandas and set up special teams and emergency response mechanisms," he said.