Terrier is a type of dog rather than a single breed. The name comes from the Latin terra, meaning earth, because these dogs were developed to hunt rats, foxes and other vermin, often by digging into burrows. Dozens of breeds share the label, from tiny Yorkshire Terriers to the much larger Airedale, and shelters use it for dogs that look terrier-like but have uncertain ancestry, often mixes of Jack Russell, Rat, Cairn, Schnauzer or Chihuahua lines.
Most adoptable terriers are small to medium dogs with wiry or smooth coats and a lively, confident outlook. Many are affectionate and loyal companions with big personalities, though common terrier habits include barking, digging, chasing small animals and a determined, independent streak. An individual dog's size, coat and energy depend on its ancestry, so a shelter's notes and a meeting say more than the label.