Panda celebrates 3rd birthday

"Every time I see the cute look in an animal's  eyes, my heart melts, which deepens my dream of becoming a veterinarian," Zhang said.

Another volunteer, Kuang Jing, and his family also came to celebrate Pang Niu's birthday.

"I hope to spread love, share knowledge of panda protection and grow up through volunteering," Kuang said.

Ye Qian in Beijing contributed to this story.