Does a West Highland White Terrier have double coat?

No, West Highland White Terriers do not have a double coat. They have a single coat, which is short, dense, and wiry.

While it may appear thick, their coat is actually made up of only one layer of hair, which is why they are considered a "single coat" breed. This means they don't shed as much as breeds with a double coat, but they still require regular brushing to keep their coat healthy and free of mats.