Dog fur comes in short coats, long coats — and everything in between — and ranges from curly to straight, puffy to wiry, bald to long. Some dogs come equipped with dreadlocks and a few have no hair at all (or very little)!
Dogs basically have two types of coats:
Double coat: Most dogs have a top coat is composed of stiff guard hairs, which tend to be naturally water-repellent. The top coat protects the dog’s skin and his undercoat, which is a fleecy or downy type of fur a bit shorter than the top coat. The undercoat serves as insulation to keep the dog warm during cold or inhospitable weather. The dog sheds (or blows out) the undercoat twice a year — it’s a seasonal thing.
Single coat: Just a top coat does for these dogs, who generally shed less than their double-coated counterparts.
You can tell what kind of coat your dog has by parting the hairs to see whether he has a longer, harsh coat combined with soft, downy fur — a double coat — or the same kind of fur throughout, which makes him single-coated.
In the same way there are different types of coats, different coats have different textures:
Smooth: A smooth- or short-coated dog has very short hair that lays back against his skin — Dalmatians and Bulldogs are examples. A smooth coat can be either double-coated or single-coated. These coats tend not to be much of a hassle when it comes to grooming — even though they do shed.
Wire: The wire, or broken coat is wiry on the outside and often has a soft undercoat on the inside, but it can be a single coat. Wire coats are wavy looking, but when you pet them, the hair feels a bit coarse. Think Terrier when you think about wiry coats.
Curly: The curly-coated dogs are few in number, but you’ll recognize them. They’re the Poodles, the Portuguese Water Dogs, and the Irish Water Spaniels. These dogs have curly coats that require extreme maintenance, including clipping and brushing.
Corded: The fur on these coats are twisted into dreadlocks. These coats need a fair amount of work upfront to prevent the hair from tangling into mats. Dogs with corded coats include the Puli and the Komondor. Poodles can also be corded.