Cat hair loss can happen for all sorts of reasons. As an owner, it can be quite alarming to suddenly see bald patches appearing on your kitty and have no idea why this might be happening.
This page goes through the most common causes of hair loss in cats, together with the symptoms and treatment.
A lot of this information in books etc. is often riddled with medical jargon, so I've tried to simplify it into plain English as much as possible.
The cause of the hair loss will need to be determined by your vet; depending on Kitty's symptoms, the vet will perform various tests to identify the problem so they then know how best to treat it.
Some of the main things your cat can become allergic to are listed below.
1) Allergic and irritant contact dermatitis
(Inflammation of the skin following direct contact with something your cat is allergic to)
Cats can develop allergies to all sorts of things that come into direct contact with their skin; carpet deodorizers, rubber, laundry products, medications applied to the skin, metals... and many more things.
These allergies usually build up over time following prolonged, repeated exposure (though an allergy to a medication may develop much quicker.)
Symptoms of feline allergies in addition to hair loss usually include itching, reddening and sometimes blistering of the skin in the affected area.
Treatment involves trying to reduce or eliminate the cat's exposure to the thing that's causing the reaction (the allergen,) and sometimes also steroids and anti-histamines, which help to reduce inflammation and the allergic reaction.
2) Allergic inhalant dermatitis
(Inflammation of the skin due to your cat inhaling something he's allergic to)
Cats can develop allergies to things such as house dust, mold, mites and pollen.
Symptoms in addition to hair loss include reddened ears, excessive licking of the feet, itching, blistering, skin infection and excessive sneezing.
Treatment includes reducing the exposure to the allergen, steroids, anti-histamines and special shampoos.
3) Flea allergy dermatitis
(Inflammation of the skin due to excessive sensitivity to flea bites)
Some cats have a very strong reaction to bites from cat fleas. It's the saliva of the flea that causes the reaction.
Symptoms include hair loss, severe itching, redness, development of scaly, crusty areas and sometimes blistering and infection.
4) Food allergy dermatitis
(Inflammation of the skin due to excessive sensitivity to certain foods)
Some cats can develop allergies to certain foods - often foods that are heavily processed and full of additives and preservatives.
Symptoms in addition to hair loss include reddened ears, excessive licking of the feet, itching and blistering and infection in certain areas.
Treatment involves cutting out the responsible food(s) - this is usually done by a process of elimination.
1) Facial alopecia
(Loss of hair on the face above the eye)
This is normal, and usually happens to cats when they are around 18 months old. It's more noticeable in short haired, dark colored cats.
No treatment is needed for this type of cat hair loss as long as there's no obvious reddening, scaling, infection etc. present.
2) Parasitic skin diseases
(diseases caused by various bugs that live on or burrow under the skin)
Parasites that can live on your cat include the mange mite, lice, ringworms, yeast and fungi. Your vet will determine which one your cat has.
Symptoms of parasitic infections may include cat hair loss, itching, scaling of the skin, redness and crusting.
Treatment depends on the parasite that's causing the disease, and will often involve a combination of direct skin treatment and tablets.
(Over-active thyroid gland)
An over-active thyroid gland produces too much of a hormone called thyroxin. One of the symptoms of this is hair loss and oily skin; about a third of cats with hyperthyroidism will develop these symptoms, and will groom themselves excessively.
Excessive exposure to the sun will cause reddening of the cat's ears and sometimes nose, followed by scaling of the skin. Repeated, prolonged exposure may result in cancer developing. Click here for advice on how to prevent this, and for information on other cat skin problems.
There are many more, not so common causes of cat hair loss too. It helps to know the main causes of hair loss in cats, but ultimately you and Kitty will likely need a trip or two to the vet to figure out why he's losing his hair.