The Formosan Mountain Dog (or Formosan) is a breed or landrace of small or medium dog indigenous to Taiwan. These dogs are also known as Taiwanese Dog/Canis, Taiwanese Native Dog or Takasago Dog. They are well-adapted to the uneven and thickly forested terrain of Taiwan, having become a semi-wild breed prior to the arrival of several colonial reigns and foreign powers. Notwithstanding these adaptations, Formosans retained the potential to be trained, and are now used as hunting dogs, guard dogs, stunt dogs, rescue dogs or simply as companions. Formosans are classified into one medium type and two small types.
However, now the pureblood Formosan Mountain dog is still close to extinction due to limited conservation efforts of the Taiwanese and their government. Native Dog is the common name in Taiwan nowadays to indicate that the dog is an offspring of Formosan with foreign dogs, it is commonly confused with Taiwan Native Dog.