What causes a domestic cat to shed their fur? People want to know. And on the internet, they’ve been told a million times 😕 . It’s my turn. You have to answer the question from two standpoints. Firstly, you have to ask whether the cat is healthy or unhealthy. And if the answer is healthy, you have to look at the normal reason for shedding hair. I address these reasons separately.
Health problem causing hair loss
Too much female hormone in the system can slow the growth of hair. Also, not enough thyroid hormone can impair the growth, texture and lustre of a cat’s coat. There is then the question of whether the cat has parasites, is suffering from vitamin deficiency or general ill-health, all of which may cause the coat to be too thin and brittle. The poor condition of a cat’s coat is a possible symptom of ill-health and you should see a veterinarian. This is the advice of the authors of the excellent book Cat Owner’s Home Veterinary Handbook.
RELATED: Hair loss in cats.
Healthy cat
Some people believe that shedding fur is caused by seasonal temperature changes. Logically, ambient temperature must be the underlying reason because a thicker coat protects a cat when it’s cold and a thinner coat allows a cat to be more comfortable when hot. But the trigger is ambient light not ambient temperature. Although of course they are linked.
When a domestic cat is exposed to increase ambient light such as in the spring the cat will shed fur. Both neutered and unneutered cats are affected. As mentioned, more ambient light and an increase in ambient warmth go together anyway.
This leads to the conclusion that cats who are allowed outside during the seasons when there are longer hours of sunlight will shed hair and it may last for weeks. For outdoor cats this will start in late spring. For indoor/outdoor cats it may start in summer. They shed and grow a new coat.
The coat will start to thicken when the days start to become shorter in the fall and winter. Indoor cats who are not exposed to sunlight my shed fur lightly and grow a new coat year-round.
Indoor/outdoor cats with double coats shed their undercoat in a patchy way. Apparently, this does not happen with full-time indoor cats. Cat owners should remove dead fur with a comb to prevent irritation. Human grooming is a great way to bond as well. The same goes for flea combing.
Living outdoors
It is also common sense and to be expected that cats living outdoors will grow a heavy coat for insulation and protection. The classic evidence of this is the well-known Maine Coon cat which has its origins in the barn cats of the state of Maine and further up the coast in Boston. Thye are well known for their shaggy medium-longhaired coats. We can perhaps put that down at least in part to 400 years of evolution in America after they were imported from Europe with the first settlers.
Hair growth
For the sake of completeness, I will briefly discuss hair growth. It occurs in cycles. The anagen phase is when there is rapid growth. This is followed by slower growth and then a resting phase called catagen. During this phase mature hair remains in the follicles and eventually detaches. When a domestic cat sheds his coat young hair pushes out the old hair and the cycle restarts. This last phase is called the telogen phase. Hair grows at about one third of an inch or 8 mm monthly.
