Puppy Fur - Growth and Function

Tilt Shot Of Dog Sleeping On Sofa At Home
Philip Thompson / EyeEm / Getty Images

Puppy fur is made up of individual hairs. The characteristics of a dog's coat depends on the texture and color of the individual hairs, which are thread-like structures made of keratin that grow outward from hair follicles in the skin.

What Is Fur?

Fur serves as a protective barrier that shields the puppy’s skin from the elements, regulates body temperature, and protects puppies from sunburn, heatstroke, frostbite, and hypothermia. Hair also acts like a candle "wick" to route scent chemicals related to identification and sexual status, sending scents from the skin into the air.

All healthy dogs have fur, but the amount and type of hair coat varies in individuals and from breed to breed. Even the hairless Chinese Crested dog has sparse hair on the face, feet, and tail.

What Is Hair?

Hairs are composed of the hair shaft, which is the visible portion of the hair, and a root generated by a hair follicle within the skin. Dogs have compound follicles, which means as many as 15 hairs can grow from a single pore. People have simple follicles which produce only one hair for each pore.

Dogs primarily have 2 kinds of hairs, characterized by length and diameter. Guard or primary hairs are the longest, coarsest hairs of the outer coat. Secondary hairs of various lengths make up the undercoat. The undercoat is soft, short cotton-like fur that's curly or crimped. All types of hairs may sprout from a single compound follicle.

The length of the hair shaft and the ratio of guard to undercoat hairs varies from breed to breed. These differences, as well as a variety of colors and patterns, produce each dog's distinctive coat.

Dog portrait
© Jackie Bale / Getty Images

How Fur Grows

Each hair grows from the root in a predictable cycle of growth. The growing phase is called the anagen phase which is followed by the catagen phase in which the root detaches from the follicle, and a resting period termed the telogen phase. Old loose hairs in the telogen phase are pushed out—called shedding—by new hairs as the anagen phase begins again. The fur that is shed is composed of telogen hairs.

A single human hair may grow for up to six years before being shed and replaced by a new one. The growth cycle of your dog’s hair is much shorter and more synchronized, which accounts for the massive seasonal shedding some dogs experience. Fur growth cycles can vary from breed to breed. Breeds that shed more tend to have more follicles in the telogen phase. The "non-shedding" breeds like the Poodle and some terriers, have single layer coats with hairs that actually grow for several years before being replaced. This is because they have more follicles in the anagen phase most of the time.

A healthy coat is possible only with proper nutrition and good overall health. Your puppy's coat retains its healthy glow from the proper balance of oils in the skin. Poor nutrition may be reflected in the skin and hair coat by dry, lifeless fur or abnormal hair loss. These can also be signs of underlying health problems. Grooming is beneficial for all dogs and particularly important for dogs with thick long coats.

Puppy Whiskers

Whiskers are the thick, long, wire-like hairs that protrude from the dog's face. Also called vibrissae or sinus hairs, whiskers are specialized hairs that are long, supple and thick; they may also appear as groupings of short stiff bristles.

Whiskers are much more developed in animals that hunt during the night or low-light times. They act as feelers and are seated deep in the skin where they trigger nerve receptors at the slightest touch.

Dogs typically have whiskers in four places on each side of the head and two on the lower jaw. The most obvious are those on each side of the dog's muzzle, where whiskers grow in rows; they provide tactile information when the dog is sticking his muzzle in and around objects.

Whiskers above each eye act like extended eyelashes. They prompt a protective blink reflex if touched. A clump of whiskers is located on each cheek and a smaller one near each corner of the mouth. Lastly, the dog has a tuft beneath the chin. These strategic locations provide extra-sensitive sensory input from the dog's environment and may help with activities including tracking behavior, locating objects, balance and orientation of the head, protection from surrounding objects, and more. For this reason, whiskers should be treated with care and should never be trimmed.

Portrait Of Cute Puppy
Nattakit Kunchitvaraonont / EyeEm / Getty Images
Article Sources
The Spruce Pets uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Why does my pet shed? American Animal Hospital Association.