Cat hair loss, also known as alopecia, can be an alarming condition if the amount of hair your cat is losing seems excessive. Normal shedding occurs due to temperature changes, and as hair follicles change, dead hair is released so as not to cause irritation. Many diseases, infections and conditions can cause excessive cat hair loss, usually in local areas or patches. If a cat's coat hair is patchy, rough or pulls out easily, there may be an underlying condition that requires attention.
Hot Spots
Cat hair loss due to the emergence of hot spots is a very common problem. Hot spots are areas on the skin that become infected or inflamed due to a parasitic infection, allergic irritation or other issues that may cause obsessive licking or scratching. Cats will focus on the area in question obsessively, until it worsens to the point of open sores and hair loss. Hot spots are caused by a number of factors including fleas, mites, dermatitis, food allergies, thyroid problems or direct contact with a toxic substance. Treatment for hot spots usually includes a topical antibiotic, as well as further diagnosis of any secondary infection or disease.
Ringworm
Ringworm is a very common cause of cat hair loss in the form of circular patches that tend to expand in size. Ringworm is not a worm, but a fungal infection that is highly contagious and takes months to resolve itself without treatment. This infection causes spots that may cause itching, and scaly patches on the skin. The appearance of ringworm is very similar to that of mange, but will most likely be treated with an anti-fungal topical medication.
Mange
Mange in cats is caused by an infestation of mites. Mange is generally much more irritating to a cat than ringworm, but causes hair loss in much the same way. Patches will form on the skin that are devoid of hair, and are usually red, inflamed and may be scaly. These patches can appear on the eyelids, head, ears and neck, but may also be seen on the body and legs. A topical insecticide should be recommended and if generalized mange is suspected, a cat may be screened for additional diseases that may affect the immune system. Feline leukemia, feline immunodeficiency virus, diabetes or a history of corticosteroid use can all lead to an in ability to fight off an infestation of mange-causing mites.
Hormonal Hair Loss
Cat hair loss due to hormones, often termed as endocrine alopecia, may be caused by a deficiency in hormones that control the growth of hair. Conditions leading to abnormal levels of any hormones which play a role in the endocrine system, such as estrogen, testosterone or thyroid hormones, may cause cats to experience hair loss, or thinning of hair in various places on their bodies. A pattern will usually develop that is similar on both sides of the body.
Psychogenic Alopecia
Occasionally, when cats experience situations which lead to anxiety or stress, they will groom to the point that excessive hair loss occurs. If no secondary conditions are suspected, an Elizabethan collar, designed to keep cats from licking or scratching certain areas, will help to determine if obsessive grooming is the cause.