Cat Hair Loss

There are usually four common disorders that cause cats to lose their hair. These are Addison’s disease, Cushing’s disease, Hyperthyroidism, and Hypothyroidism.

Addison’s Disease

Addison’s disease is caused by hypoadrenocorticism – a serious decrease in the adrenal activity. This decrease can cause lethargy, serious change in skin tone, and hair loss. Hair loss is one of the first and more prominent signs of this condition.

Addison’s disease is a very uncommon disease in cats and can be brought on by lymphsarcoma cancer or by an underlying disorder of the pituitary gland. Unfortunately this disease is not easily treated in cats. The vet will do what he can to make the cat comfortable.

Cushing’s Disease

Cushing’s disease is one of the more common causes of hair loss in cats. Other symptoms to look for are increase in appetite and thirst and mild to severe lethargy. The cat will lose his hair bilaterally. This means that the hair missing on one side will also be missing on the other side. The hair loss is usually centered near the mid to lower abdomen – but it is possible to occur anywhere on the cat’s body.


Hyperthyroidism is a very common disorder in cats and can lead to hair loss. Other symptoms include weight loss, an end to grooming, increase in thirst and appetite, and increase in urination. This condition can be easily controlled with medication or radioactive iodine therapy.


Hypothyroidism causes a cat to lose its hair due to a hormone imbalance and too much grooming. A cat that suffers severely from this condition will lick and bite their skin until it is dry and flakey. That is when tufts of hair will begin to fall out. Other symptoms include increase in appetite, severe weight gain, very dry coat, and lethargy.

If your cat is suffering three of these symptoms and is also vomiting you should contact your vet immediately. It could be a sign of Feline Kidney Disease.

Other Cat Hair Loss Problems

If your cat does not have any of these disorders you might find that the issue causing the hair loss is related to allergies.


It is possible for your cat to be covered in too many fleas from being outside too much. Your cat may find that they have sensitive skin and they will lose their hair from scratching and biting at the fleas. The itch will become unbearable to some cats and they will focus on nothing else. They will go so far as to pulling their hair out to get to the itching skin. Cats who have fleas should be treated immediately in order to avoid more problems.

Notoedres Cati

It is possible for cats to lose their hair over simple problems known as notoedres cati. This is a parasite that causes them to lose their hair. The parasites will cause the cat to lose its hair on its neck, ears, eyelids, and other areas on its upper body.