Overview
The skin (cutis) covers the whole body surface and is continuous with the mucous membranes at the natural openings. It works as a physical, chemical and microbiological barrier and takes part in thermoregulation and in the perception of touch, temperature, pain and itch. In cattle it is thick, especially over the dorsal neck and trunk, and beneath it the cutaneous trunci muscle (m. cutaneus trunci) lets the animal twitch the skin to shake off insects.
Layers
- Epidermis: keratinised stratified squamous epithelium without blood vessels; it is thicker on the muzzle and the skin of the digits.
- Dermis: dense connective tissue with collagen and elastic fibres; it holds vessels, nerves, hair follicles, arrector pili muscles and glands. This layer gives bovine skin its thickness.
- Hypodermis (tela subcutanea): loose connective tissue with fat.
Hair and glands
- Coat: simple hair follicles, with a single hair per opening. Coat length and density vary with breed and season.
- Sweat glands: apocrine, associated with the hair follicles. Unlike the dog and cat, cattle lose heat by sweating as well as by breathing.
- Sebaceous glands: open into the follicles and lubricate hair and skin.
- Dewlap: fold of skin on the ventral neck, very well developed in zebu cattle (Bos indicus).
Specialised regions
- Muzzle (planum nasolabiale): hairless area between the nostrils and the upper lip. The nasolabial glands in its dermis keep it moist and cool; its pattern of grooves and ridges is unique to each animal and can be used to identify it.
- Udder, horns and hooves: modified skin structures described separately.
Clinical relevance
- Dermatophytosis (ringworm): infection by Trichophyton verrucosum, mainly in calves; it causes circular lesions with greyish crusts, often around the eyes. It is a zoonosis.
- Lumpy skin disease: disease caused by a capripoxvirus and spread by insects; it causes firm skin nodules and fever. It is notifiable.
- Papillomatosis: warts caused by bovine papillomavirus (BPV), common in young animals, on the head and neck.
- Dermatophilosis: infection by Dermatophilus congolensis, favoured by prolonged wetting; it forms thick crusts that pull out tufts of hair.
- Ectoparasites: lice and mange. Chorioptes mainly affects the tail base, perineum and limbs; Psoroptes causes extensive, very itchy lesions on the body; Sarcoptes can also affect people.
- Photosensitisation: dermatitis of unpigmented skin exposed to sunlight, caused by photodynamic plant substances or, in the hepatogenous form, by liver damage that prevents phylloerythrin from being cleared.