The Cairn Terrier comes from the Scottish Highlands, where farmers and hunters used it to slip between the rocks of cairns and bolt foxes and vermin. That job explains the sturdy, short-legged build, the broad foxy head, the small upright ears and the harsh, weather-resistant double coat. Colors run wheaten, red, gray, brindle or nearly black, never white, and brindle coats often keep changing for years.
Cairns are cheerful, curious and confident, usually friendly with people but independent enough to ignore a request they find dull. Digging, chasing small animals and barking when bored are common. The coat sheds little and stays tidy with weekly brushing and occasional stripping, and a quick brush after dusty walks keeps grit out. Dogs vary, so each Cairn's own personality matters more than the breed description.