Westies share their history with the Cairn, Dandie Dinmont, Skye and Scottish Terriers; All of these dogs are considered branches of the same breed. The West Highland White Terrier originated in Scotland. Westies were used for hunting fox, badger, and otter and for killing vermin such as rats. That's why they're known as ratters in the dog world.
Colonel Edward Donald Malcolm of Poltalloch, Argyllshire,Scotland is credited with originally breeding Westies. Legend has it that his favorite hunting dog was mistakenly shot on a fox hunt so he decided a white terrier would be easier to see and less likely to be mistaken for game.