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Hair loss in cats
Last reviewed: 08.07.2025

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Cat hair grows in cycles. Each follicle has a period of rapid growth (anagen phase), followed by slower growth and then a resting phase (catagen phase). During the resting phase, the mature hair remains in the follicle and eventually separates at the base. When the hair falls out (telogen phase), new hairs push out the old hairs and the cycle repeats. On average, a cat's hair grows 8 mm (0.33 in) per month.
There are hairless cat breeds such as the Peterbald (born with some hair that falls out until about age two) and the Sphynx (their body is covered in fine fluff, they may have hair on their nose, toes and tail). The lack of hair in these cats is caused by a genetic mutation, it is not a disease.
Too much female hormones in the body can slow down hair growth. Too little thyroid hormone often impairs the growth, texture, and gloss of a cat's hair. Poor health, debilitating disease, hormonal imbalances, vitamin deficiencies, and parasites on or in the cat can cause the hair to become sparse and brittle. If you suspect that your cat's hair is not in good condition, you should consult your veterinarian. Poor hair condition always reflects a systemic disease.
Some breeds of cats have naturally thicker coats. The environment also has a definite effect on the thickness and quantity of coat. Cats that live outside in cold weather will grow a thick coat for insulation and protection. During this period, extra fat in the diet is desirable because fat provides a more concentrated source of energy for coat growth. Fat also helps with the absorption of fat-soluble vitamins, provides essential fatty acids for healthy skin and coat, and improves the palatability of the food. Concentrated fatty acid supplements are available. A cat's diet has too much fat when its stools become soft.
The average indoor cat does not need fat supplements. As a word of caution, do not give fat supplements to cats with pancreatitis, gallstones, or malabsorption syndromes. Excessive fat supplements can interfere with the metabolism of vitamin E. Before making long-term changes to the fat content of your cat's diet, discuss such changes with your veterinarian. Always consult with your veterinarian before giving your cat any supplements. This is to ensure that a well-balanced diet is not disrupted.
Hair loss
Some people believe that seasonal temperature changes cause hair loss in cats. In reality, changes in natural light have a greater effect on hair loss. The more exposure to natural light, the more hair loss. This applies to both spayed and unspayed cats.
In cats that spend all their time outdoors, the increase in daylight hours in late spring triggers a shedding process that can last for several weeks. Cats that go outside for part of the day typically shed and grow new fur in early summer. In the fall, as the days get shorter, the fur thickens for the winter. Cats that live indoors and are constantly exposed to light may shed and grow new fur little by little throughout the year.
Spotted coats are the most common coat patterns in the wild. Tigers are striped (elongated spots), leopards are spotted, and lions have spots when they are young. It is also very common in domestic cats, such as the American Shorthair.
Most cats have a double coat, consisting of long, large guard hairs and a soft, fluffy undercoat. The exceptions are the Devon Rex and Cornish Rex. Rex cats have a single coat, consisting of small, curly hairs. Selkirk Rex cats have slightly longer, curly hairs. These cats shed, but less than cats with normal hair. This is a dominant mutation.
Wirehaired cats have very curled fur, including whiskers. This is a dominant mutation. The fur is rough and harsh to the touch.
When a double-coated cat begins to shed, the undercoat sheds in patches or patches, giving the coat a moth-eaten appearance. This is completely normal. Cats that are never allowed outside shed year-round and do not experience this. When shedding begins, remove as much dead hair as possible during daily brushing to prevent skin irritation.
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