Smooth Coat Chihuahuas should be  brushed with a small bristle brush or grooming glove in the direction of hair growth twice a week to minimize shedding. Grooming is slightly more complicated for Long Coat Chihuahuas. The coat should be lightly misted with diluted coat conditioner before brushing to prevent static build  and coat breakage. The shorter coat on the body and legs should be brushed with a grooming glove or a small slicker brush.

Use a small pin brush for the furnishings, gently working from the tips of the hairs to the roots. Go through the entire coat with a fine-tooth metal comb after brushing. Pay particular attention to the rear feathering, known as the skirts, and the fine hair under each ear, called the earrings.

Both of these areas are prone to matting. If you discover a mat, do not pull at it or attempt to cut it out. Pulling will make it even tighter, and it is very easy to accidentally cut the skin. Saturate the mat will tangle remover and gently work at it from the edge with one tooth of the comb.

Hair is formed from the protein keratin and grows from follicles in the dermis or inner layer of the skin. Human follicles produce a single hair, but most animals, including dogs, have compound follicles, which produce multiple hairs. Each follicle produces one large main guard hair, which serves as a protective top layer, and several smaller, softer hairs, which form the undercoat and provide insulation.

Dog coats vary enormously in length, texture, and density because of the wide mixture of hair types that make up each breed’s outer coat and undercoat. This is also subject to some degree of variation within each breed.

Each follicle also has a sebaceous gland to produce skin oils. Brushing does more than just eliminate dead hair and tangles. Skin oils keep the skin supple and prevent the coat from drying out. Frequent brushing distributes these lubricating oils over each shaft of hair.

Shedding

Brushing your Chihuahua will also help to minimize shedding. Dogs that spend most of their time indoors tend to shed continuously. However, shedding does become more pronounced in the spring and fall because hair growth cycles are linked to the changing hours of daylight. In addition to seasonal fluctuations, hair growth is also influenced by nutrition, age, stress, general health, and hormones. Females usually shed conspicuously after being in season or nursing a litter of puppies.

Regardless of its density or texture, hair grows in four distinct cycles. During the active anagen phase the hair grows in length through the addition of cells to the bottom end. At the end of this stage ends the hair enters the dormant catagen phase and transitions from growth to resting. During the catagen phase some hairs will detach and die although they will remain in the follicles. The presence of these dead hairs causes the coat to become dull.

Brushing to pull them out of the follicles will keep the coat shiny. It also speeds up the expogen shedding phase and stimulates the start of the transitional telogen phase as the ofllicle prepares for the next cycle of new hair growth. Short-haired breeds like Smooth Coat Chihuahuas tend to shed more because it takes less time for short hairs to complete an entire growth cycle.