The Cairn Terrier is a breed of dog of the terrier category. It is one of the oldest terriers, originating in the Scottish Highlands, used for hunting burrowing prey among the cairns.
The Cairn Terrier has a harsh, weather-resistent outer coat that can be cream, wheaten, red, sandy, gray, brindle, black, or black and tan. This breed has a soft, dense undercoat. If white, the breed name is the West Highland White Terrier rather than the Cairn Terrier.
Cairn Terriers are intelligent, strong, and fearless. Like most terriers, they are stubborn and love to dig after real or imagined prey. These dogs are generally healthy but many have allergies. This breed also suffers more than usual from dislocated kneecaps and inherited eye diseases. The breed stands between 9 and 13 inches (23-33 cm) at the withers and weighs 13 to 18 pounds (6 to 8 kg).
The dog named Toto in the 1939 screen adaptation of The Wizard of Oz is a Cairn Terrier.