CHENGDU - Pan Pan, the world's oldest male panda, celebrated his 31st birthday in a panda protection center in southwest China's Sichuan Province on Thursday.

Pan Pan, whose age is equivalent to about 100 human years, cooled down with a three-tier ice sculpture while staff at the Dujiangyan base of the China Research and Conservation Center of the Giant Panda sang "Happy Birthday."

This year's celebration was low key compared with Pan Pan's previous birthdays, as his fans were not allowed to attend. The elderly panda has been moved to quiet, restricted quarters since he was diagnosed with squamous cell carcinoma, a type of cancer, in June, according to Wei Ming of the protection center.

He also suffers from a declining immune system, cataracts, serious tooth wear, and aging organs. Due to Pan Pan's numerous health issues, doctors have adopted conservative treatment, rather than surgery, to deal with the tumor around his anus.

Experts are keeping a close eye on his health and adjusting his diet daily. Thanks to their care, the panda's weight has remained within the normal range at around 105 kilograms.
He is in stable condition, and the tumor has shown no signs of spreading, according to Wei.

Pan Pan was born in the wild in Sichuan's Baoxing County in 1985. He has been living in captivity since he was just a few months old.

Pandas are notoriously difficult to breed in captivity, but Pan Pan has fathered many cubs over the past 20 years. He has more than 130 descendants, accounting for one-fourth of the world's captive-bred panda population.