large, powerful, and agile yet quiet breed of working dog originally used to keep poachers off British estates, and kill the trespassers if need be; coat is short, dense, and weather-resistant and can be either red, fawn, or brindle; all colors usually have a black mask; ears are high-set, small, V-shaped, and carried close to head; muscular tail is long and tapering; eyes are smallish and dark; adult stands 24–27 in. (61–69 cm) tall at shoulders and weighs 100–130 lbs (45–59 kg); fearless with strangers, this breed is docile and loving with its master; puppies are often clumsy and naughty and should be properly disciplined before they reach adulthood; breed developed through crosses with the bulldog in the late 1800s in Great Britain,