A Dandie Dinmont Terrier is a small Scottish dog breed in the terrier family. The breed has a very long body, short legs, and a distinctive topknot of hair on the head. They are friendly but tough, and are suitable for interaction with older children. There are breed-specific health concerns: they can be affected by spinal problems due to their elongated body, and the breed is affected by canine cancer at a higher than average rate.

Terrier is a type of dog originally bred to hunt vermin. A terrier is a dog of any one of many breeds or landraces of the terrier type, which are typically small, wiry, game, and fearless. There are five different groups of terrier, with each group having different shapes and sizes.