There are two forms of seborrhea: oily (oleosa) and dry (sicca). A combination of both is frequent. A change in the amount and quality of the oily skin secretions (sebum) caused seborrhea. An imbalance between new and dying skin cells causes the flakes on your cat's coat and this aspect of skin peeling.
Dandruff can be observed in cats with no dermatological disease, usually those that have not groomed properly due to the following reasons:
- wearing an E-collar for a long time,
- obesity ; some cats are too fat to reach every body site and groom properly,
- too long a coat to be able to keep it clean,
- general sickness with depression, or endocrine disorders,
- spine pain which prevents them turning around properly.
Many dermatologic causes can also be possible: fungi such as ringworm or Malassezia dermatitis, parasitic skin disease (cheyletiellosis, demodecosis), lymphoma of the skin...
Oily skin exudes a waxy, greasy substance and you may see comedones, often giving cats an unpleasant smell. With dry seborrhea, dandruff is more frequent and a lack of sebum irritates the skin. Skin hyperpigmentation and hair loss are also common.
The damage to the natural protective skin barrier creates a favourable place for bacterial or yeast infections and itch may appear too.
Feline acne is a specific type of feline seborrhea that is caused by overactive sebaceous glands on a cat's chin leading to blocked hair follicles and comedones (blackheads). The affected area can also become infected with bacteria in some cases and may also itch or irritate. Cat's affected with feline acne have thicker more swollen skin due to the changes described - so it's worth checking the skin more closely if you feel your cat has developed a big chin.