Dog Owner's Home Veterinary Handbook.pdf - Mr. Walnuts

102 •DOG OWNER’S HOME VETERINARY HANDBOOK
Guard hair
Accessory hair
Dermis
Subcutaneous fat
The Dog’s Coat
The quality of a dog’s coat is controlled by a number of factors, including hormone
concentrations, nutrition, general health, parasite infestations, genetics,
and the frequency of grooming and bathing. Dogs who live outdoors in
cold weather grow a heavy coat for insulation and protection.
Hormonal disorders such as hypothyroidism, hyperestrogenism, and
Cushing’s syndrome slow or suppress hair growth, making the coat appear thin
or sparse. A protein deficiency caused by parasites, poor diet, or ill health may
cause the coat to be dull, dry, brittle, and thin.
If your dog’s coat is below par, have her checked by your veterinarian. Poor
coat quality is often an indication of a systemic disease.
HAIR GROWTH AND SHEDDING
Cross-Section of the Skin
Epidermis
Root of hair
Hair follicle
Sebaceous gland
Dog hair grows in cycles. Each follicle has a period of rapid growth (the anagen
phase), followed by slower growth and then a resting phase (the catagen
phase). During the resting phase, mature hair remains in the follicles and
eventually detaches at the base. When the dog sheds her coat (the telogen
phase), a young hair pushes out the old hair and the cycle begins anew. The
average dog takes about four months to grow a coat, but there are individual