American Tundra Shepherd (ATS) is a rare breed and officially was bred in the late 1960s in the United States as a military K-9 dog by Frank Catania. This large breed can weigh from 100 to 140 pounds and has a height of from 27 up to 33 inches. They can live indoors, but they have a very high energy level, so they require lots of exercise and long daily walks. They are very smart and intelligent, and they make excellent service dogs and police dogs. With early and proper training and socialization, they can be taught to behave greatly with young children; otherwise, they can be hardly handled due to their large size and aggressive nature.