The honest answer for a Chihuahua is that it depends on the coat, because the breed comes in two distinct types. A smooth-coated Chihuahua, the short glossy kind, needs brushing about once a week. A long-coated Chihuahua needs two to three sessions a week. Both are small jobs, a few minutes at most, but the long coat's fine feathering genuinely tangles, while the smooth coat's needs are mostly about shedding and shine. Either way, this is the smallest dog breed in the world, and everything about its grooming should be scaled down and gentle.
The smooth coat: a weekly five minutes
The smooth Chihuahua's hair is short, soft, and close-lying, often with a modest undercoat that sheds more than people expect from so little dog, particularly in spring and fall. A small soft bristle brush or a rubber grooming mitt made for toy breeds, used with the lightest pressure, lifts the loose hair and polishes the coat in a few strokes per side. Work in the direction of growth and let the brush do the work; pressing a stiff tool down on a Chihuahua reaches skin almost immediately. Most smooth coats are fully done in under five minutes, and many Chihuahuas will tolerate the mitt version happily in a lap, which is the natural grooming station for this breed.
The long coat: feathering that needs a rhythm
The long-coated Chihuahua carries a soft, flat or slightly wavy coat with feathering on the ears, the backs of the legs, the feet, and a full plume of a tail. That feathering is fine and silky, and it knots behind the ears and where the legs meet the body if it goes unbrushed for a week. Two to three sessions a week with a small pin brush, followed by a fine comb through the feathering to confirm it is clear to the skin, keeps the coat flowing instead of clumping. Tease tangles apart with fingers first; yanking a comb through a knot on a two-kilo dog is painful and teaches the dog to dread the brush. Bathe only after a full brush-out, and dry the feathering gently rather than rubbing it into fresh tangles with a towel.
Handling a dog who can be nervous about grooming
Chihuahuas are alert, sometimes anxious little dogs, and cold hands, looming tools, or being held too firmly can make brushing a weekly argument. Warm your hands, let the dog sit in your lap or on a familiar blanket, keep sessions short, and end while things are still going well. Puppies should be brushed in tiny, pleasant doses from their first weeks at home so the adult routine is unremarkable. A Chihuahua who trembles through grooming despite patient handling, or whose skin is red or flaky under the coat, is worth discussing with your veterinarian, because discomfort and skin trouble hide easily under even a small coat.
Little dog, real skin checks
The brushing session is also when a Chihuahua's skin, so close under so little hair, can be properly looked at. Watch for dryness and flaking, which this breed shows readily in heated indoor air, thinning patches, and any small lump. Keep the delicate skin out of harsh midday sun in summer, since sparsely coated areas on a pale dog can burn.
A small job that still needs a reminder
Chihuahua grooming disappears from busy households precisely because it takes minutes. Leaving the weekly or twice-weekly session on the shared list in KinsLe under Care Teams, where it can be ticked off by whoever holds the dog that day, keeps the habit alive for the smooth and the long coat alike.