A photo taken on February 23, 2006 depicts a veterinarian from Wuhan Zoo vaccinating a panda against canine distemper. [Photo/CFP]

Another three giant pandas in North China's Shaanxi province have been infected with canine distemper after one died of the disease on Dec 9.

Shaanxi Rare Wild Animal Rescue and Research Center confirmed three pandas - Dabao, Fengfeng and Zhuzhu - as having been infected with canine distemper on Dec. 24, 25 and 27 respectively. Three other suspected cases were also found recently.

The new cases come after Cheng Cheng, an eight-year old giant panda, was found sick on Dec. 6 and died three days later.

"On December 6, a breeder conducted a routine inspection of the panda's house and saw giant panda Chengcheng suddenly fall down and start twitching. We immediately drew some blood for tests. We sent the blood sample to two different research centers and confirmed that Chengcheng was suffering from canine distemper. On December 9, Chengcheng died," said Han Xueli, director of the center.

"For giant pandas, the disease is a highly lethal infectious disease. Generally, a giant panda will be in a lot of danger if it catches the disease. The death rate is high, over 90 percent, according to statistics," said Jin Yipeng, an associate professor in the College of Veterinary Medicine at China Agriculture University.

The center has closed to the public and quarantined the sick giant pandas for further treatment.