In this April 23, 2015 photo, friends Jia Haixia, left, and Jia Wenqi work to plant a tree in a field in Yeli village near Shijiazhuang city in northern China's Hebei province. For the past 13 years, Jia Wenqi, who has no arms, and Jia Haixia, who is blind, have worked together to plant and water more than 12,000 trees near their village. (Photo by Helene Franchineau/AP Photo)

A dog welcomes a volunteer at the “Ping An A Fu” (“Safe and Happy”) Homeless Animals Rescue Center on September 11, 2006 in Nanjing of Jiangsu Province, China. (Photo by China Photos/Getty Images)

A Pomeranian dog sits in a rolling pet carrier in Hong Kong, China on September 4, 2019. (Photo by Kai Pfaffenbach/Reuters)

Qian Hao's imported Pekingese dog, Mixiu, runs in a park in Beijing, China, February 8, 2018. (Photo by Thomas Peter/Reuters)

A dog wearing a mask is seen on a street following an outbreak of the novel coronavirus disease (COVID-19), in Shanghai, China on March 22, 2020. (Photo by Aly Song/Reuters)

Dai Shuqing's husband sits among adopted stray dogs at an animal shelter on December 15, 2006 in the outskirts of Xian of Shaanxi Province, China. The animal shelter, established by animal lover Dai Shuqing, is located at an abandoned warehouse which houses some 100 dogs and costs over 2,000 yuan (about US $255) per month. (Photo by China Photos/Getty Images)

“The Tibetan Mastiff also known as Do-khyi (variously translated as “home guard”, “door guard”, “dog which may be tied”, “dog which may be kept”), reflects its use as a guardian of herds, flocks, tents, villages, monasteries, and palaces, much as the old English ban-dog (also meaning tied dog) was a dog tied outside the home as a guardian. However, in nomad camps and in villages, the Do-khyi is traditionally allowed to run loose at night and woe be unto the stranger who walks abroad after dark”. – Wikipedia

Photo: A man displays a Tibetan Mastiff he raised during the Tibetan Mastiff exposition on April 7, 2007 in Langfang of Hebei Province, China. (Photo by China Photos/Getty Images)

A Hong Kong Correctional Services Dog Unit (CSDU) officer demonstrates training at the CSDU training facility in Stanley, Hong Kong, China, 27 February 2018. The Hong Kong CSDU consists of 29 staff members divided across six dog teams. According to the department's latest figure from 2017, the average daily penal population of Hong Kong was 8,529. (Photo by Jérôme Favre/EPA/EFE)