The Cairn Terrier is one of the oldest terrier breeds, originating in the Scottish Highlands and recognized as one of Scotland's earliest working dogs. The breed was given the name Cairn because the breed's function was to hunt and chase quarry between the cairns in the Scottish highlands. Cairn Terriers tend to look similar to a Norwich Terrier, but with some differences (for example the shaggy fur). Their outer layer of fur is shaggy, but they have a soft, downy undercoat. Their ideal weight is also 4.5-7.3 kg (10-16 lb), and the height 9–13 in (23–33 cm).