[Photo by Nan Shan/ China Daily]

Now, many areas are taking measures, including establishing shelters and sterilization, to manage and control the population of these giant Tibetan dogs.

Meanwhile, animal welfare activists in Beijing are reported to have saved 21 Tibetan mastiffs and 150 other dogs from being taken to a slaughterhouse where the animals would have been sold for $5 a head.

Separately, the dogs have also had an adverse impact on the natural environment.

For instance, dongchongxiacao, or Chinese caterpillar fungus - used in traditional medicine - which grows on the Tibetan Plateau, has been destroyed by the dogs.

Also, the Tibetan mastiffs are not only eating wild animals, but also eating cattle raised by local farmers.

The Tibetan mastiffs are believed to have evolved from the gray wolf in that area over 42,000 years ago.

They are more closely related to gray wolf as compared with other dogs, according to a study by the Shanghai branch of Chinese Academy of Sciences released in 2016.