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 over several centuries to hunt rats, foxes and other vermin, often by following them into burrows. Dozens of breeds share the label, and adoptable Terriers are often mixes with Jack Russell, Rat, Cairn or Schnauzer in the family tree.
Most are small to medium, with wiry or smooth coats and a confident, lively outlook. Many are affectionate and loyal, though barking, digging and chasing small animals are common habits. That digging instinct matters in Jacksonville yards, from the Westside to Mandarin, so a secure fence is worth a close look. A Terrier's size, coat and energy depend on its ancestry, so meeting the dog says more than the label.