Curly, silky, wiry, single and double coats abound in the dog world. If your pup has a double coat, it is actually two coats of fur -- a coarse outer coat and a soft undercoat. Single-coated dogs have no undercoat.
Dogs have either single- or double-density coats. A double-density coat has outer guard hairs with an undercoat that is shorter and finer. The undercoat can be thick or thin as well as downy. Herding and working dogs usually have a double coat. Dogs with single coats have outer guard hairs, but they have no inner layer or undercoat. Examples of dogs with single coats are black pugs, Maltese and Yorkshire terriers.
Short Double Coats
The short double coat is flat with straight, coarse hair on the outside and a thin or thick undercoat. Rottweilers have a thin undercoat, but the German shepherd has a thick undercoat. Because of the double coat, brushing is necessary to remove the dead undercoat and prevent matting.
Short and wiry double-coated hair is thick and hard to the touch. Airedales, wire-haired dachshunds and Scottish terriers have this coat. A stripping comb is needed to thin the coarse, thick hair.
Long Double Coats
The long double coat has a straight and coarse outer coat and a very thick undercoat. Samoyeds and collies have long double coats. Their coats mat easily, so brushing and combing often is necessary.
The long and coarse double coat has a soft undercoat mixed into it. The shih tzu, lhasa apso and Tibetan terrier have this coat. The coat can mat easily, so frequent brushing is necessary, using slicker and bristle brushes.
Long, silky coats as seen on Yorkshire terriers, Maltese and the silky terrier are a challenge to groom because the hair is fine and mats easily even though there is no undercoat that could mat.
Dogs with curly, single coats usually have thick and soft fur. Poodles have curly coats and are hypoallergenic. They shed little and have little dander, making them a possible choice for allergy sufferers.
The soft-coated wheaten terrier is also a single-coated dog. The coat is soft and silky with no undercoat. Usually terriers have double coats.
Pauline Gill is a retired teacher with more than 25 years of experience teaching English to high school students. She holds a bachelor's degree in language arts and a Master of Education degree. Gill is also an award-winning fiction author.