Female dogs often drop their coats after a heat cycle or after whelping and most dogs will also shed after undergoing anesthesia. It is in winter that the dog's coat does its job. Muscles in the skin allow Bear to fluff his coat up, thus trapping a layer of air warmed by his body temperature between the skin and the environment. Thus shielded, Bear can choose a spot out of the wind, curl up in a ball, tuck legs under his body, cover nose with tail, and sleep outside in below-zero temperatures. Hair also protects Sassy from injury to feet, eyes, and ears.
Northern breeds tend to have hairy paws to protect their pads from ice and snow.
Some breeds have hair inside their ears or across their eyes to protect those tender parts from debris. Whiskers Whiskers are the stiff hairs on the dog's face. They occur in clusters and serve as sensory structures anything brushing against these whiskers stimulates Rusty to close his eyes, pull away, turn his head, paw his face, or shake his head. Some exhibitors trim the whiskers of their show dogs, but such trimming may limit the dog's response to his environment and detracts from the natural appearance of the pet. Color is not all black and white Skin and hair color come from special cells in the skin that produce melanin according to Mischief's genetic code for color, and the amount of melanin is governed by the animal's genetic code, a complex genetic interaction of several pairs of genes that determine color, pattern, and distribution of white hairs on the body.