Police dog Guilong patrols with armed police officers at Guiyang Railway Station, Southwest China's Guizhou province. [Photo/chinanews.com]

Guilong, born in 2007, is a Labrador trained to detect explosives at Guiyang Railway Station in Guizhou province. The dog has served during many important events, including the Beijing Olympic Games, the 70th anniversary of victory in the Chinese People's War of Resistance Against Japanese Aggression, and the G20 summit in Hangzhou. Guilong is about 10 years old now, which is equivalent to roughly 70 human years. The diligent dog will retire after this year's Spring Festival travel rush.