Hair of a dog is an important characteristic and sign of breed, an indicator of health of an animal. It performs also decorative functions, and protects a dog from cold. Breeds of dog are even distinguished on wool length therefore they are divided into long-haired, short-haired and that who have wool of average length.
Structure and functions of a woolen cover of a dog
The hair or woolen cover is one of characteristic signs of a class of mammals to which also dogs belong. Initially it performed only function of protection against cold, but as a result of selection human activity on removal of various breeds, wool, or its absence, began to perform also decorative function, having become one of signs of breed.
The woolen cover of the majority of breeds consists of strands of wood of different type. They can differ in the structure, development and appointment and are divided into an underfur, ostevy and the covering hair. The underfur consists of down hairs – thin, soft and rather short and also from semi-down, more rigid. These are integumentary hairs, the most part of a woolen cover of a dog consists of them. The underfur plays an important role in heatsaving and is especially developed at those breeds which parted in northern areas. The hair determines by Osteva appearance of a dog and her color, it consists of less dense, but longer and thick strands of wood. The hair directing ostevy is located along a backbone, on a muzzle and a back of a dog. The covering indumentum of a dog two groups – tactile and bathrooms make hair. Tactile hairs are eyelashes on centuries and the mustache growing near a nose lobe. Hair all breeds have long bathrooms not, they are well visible, for example at sheep-dogs of a sheltie and a collie. The woolen cover typical for any given breed begins to be formed with three-months age.
Structure of dog wool
Each filament strand of wood consists of a core and a root. The core deprived of sensitivity consisting of dead cells acts over the surface of skin. The root is located in a hair sack, its bulb is in the upper layer of the skin. In a bulb there is a continuous process of cell regeneration that causes growth of filaments. When the bulb dies off, the filament drops out, and on the hair sack which remained on its place the new bulb is formed after a while and the new filament begins to grow. At dogs the mass change of the filaments making a woolen cover happens two times a year that is caused by change of seasons. The surface of each filament is covered with a cuticle, inside there is a brain substance containing a pigment which defines a color of a dog. A condition of a cuticle – an indicator of the health of a dog which is correctly chosen for her a diet. At a healthy dog wool brilliant, covered with a thin layer of fat emitted by channels of the sebaceous glands located in the upper layer of the skin.