Structure and tasks of the skin in cats
All mammals - and therefore also cats - have one thing in common: the skin is their largest organ. It encloses the entire body and protects it from harmful environmental influences, e.g. from mechanical stress, but also from the penetration of microorganisms and chemical substances into the organism. With its countless nerve endings, it also serves as a sensory organ that provides information about the sensation of cold, warmth and touch to the brain.
The cat's skin consists of several layers, each with its own function: The epidermis forms the outermost layer of skin, which becomes visible when the fur is pushed to the side. Underneath lies the thickest layer of skin - the so-called dermis. The subcutis consists mainly of fat and connective tissue.
The epidermis is the uppermost layer of skin that contains, among other things, the pigment-forming cells that are responsible for the colouring of the skin coat. Although the colour and distribution of pigments are primarily genetically determined, the colour of the coat can also change with the natural ageing process as well as through UV radiation and diseases.
Numerous cells exist in the epidermis, which migrate to the surface of the skin after their formation, die and in the process increasingly harden into small, firm horny scales. The uppermost skin layer thus consists of several layers of these horny cells. As a result, they form a kind of protective coat of keratin, which is much thicker on hairless areas such as the paw. The more stress a part of the body is subjected to, the stronger the horny coat will be. Age also contributes to the growth of the horn coat.
This horny layer protects against mechanical and chemical stress and also ensures protection against the penetration of harmful microorganisms (e.g bacteria). In addition, the skin barrier prevents fluid loss.
In newborn and young kittens, the skin barrier is even more permeable than in adult cats.
The dermis is the middle layer of the skin. It consists of a dense, elastic tissue that makes the skin flexible and thus resistant. As with many mammals, the same applies to the skin of cats: the older the animal gets, the more these properties decrease.
The dermis houses a large number of blood vessels. On the one hand, these are responsible for supplying the overlying epidermis with nutrients, and on the other hand, they play a decisive role in regulating the skin and body temperature. When it is hot, the vessels dilate and are thus able to release the heat to the outside. Cold temperatures, on the other hand, cause these veins to contract in order to keep heat loss as low as possible. The dermis houses a particularly large number of sensory cells. They are responsible for perceiving environmental stimuli and transmitting them to the brain. For each type of stimulus, there are different cells that react to sensations such as touch, pain, itching, cold and warmth.
A special type of muscle also occurs in the middle layer of the skin, the hair follicle muscles (also: hair erector muscles). If the cat experiences stress, which is triggered by fear of a threat, for example, this causes the release of corresponding hormones, which in turn lead to the tension of these muscle fibres. This tension becomes visible through the standing up of the hair, especially in the neck and back area. This process is comparable to that which leads to goose bumps in humans.
The third layer of skin, the subcutis, is largely made up of fat cells, which are used to insulate the body from the cold, but also as protection from external mechanical impacts, such as bumps or cuts. In addition, the fatty tissue is a storehouse for energy and vitamins.
The skin glands
The cat's skin contains a large number of glands that secrete different fluids depending on the type. Sebaceous glands produce fat that forms an oily layer on the cat's skin. This provides a shiny coat and at the same time protects against the penetration of harmful substances and microorganisms. The highest concentration of sebaceous glands is found in the area of the lips and at the root of the tail.
Unique to cats are also the numerous scent glands, such as the circumoral glands on the lips or the temporal glands in the temporal region. The scents secreted from these glands are mainly used for communication with conspecifics. Cats often rub their heads against objects or people and thus distribute their "communicative markings".
Nature and tasks of the cat's fur
It protects the skin or the body from external influences. Besides intercepting weather influences such as moisture or cold, the coat also helps to keep parasites away from the sensitive skin. As with dogs, the cat's coat consists mainly of two different types of hair - the undercoat and the top coat. The undercoat forms another layer of insulation against cold temperatures. Therefore, it is mainly this type of hair that falls out more during the coat change in spring to allow the cat to adapt to the now warmer environment.
In cats, apart from the purely visual characteristics of the coat colours, a distinction is made between three main coat types: short-haired, medium-long-haired and long-haired. Especially in long-haired breeds such as Persian and Angora cats, the undercoat is particularly pronounced in relation to the top coat. This requires a high degree of regular and intensive grooming, also on the part of the owner, as otherwise tangles will quickly develop which can become a serious problem for the cat if they are not removed. With matted and knotted hair, the cat can no longer fulfil its own grooming routine - this can also damage the skin.
Diseases and allergies, as well as over- or undersupply of certain nutrients, can also stress the skin from the inside and weaken its defense function. A balanced supply of nutrients such as essential fatty acids, biotin, zinc and amino acids should be ensured in order to maintain the natural health of the skin.