Chihuahua
The smallest breed there is, from Mexico, and many are born with a soft spot on the skull that never fully closes. It attaches hard to one person.
Overview
The Chihuahua is the smallest breed in the world, descended from the Techichi kept by the Toltec and Aztec peoples of Mexico, and it has been a companion dog for at least a thousand years. It comes in smooth and long coated varieties.
UK data gives a life expectancy at birth of 7.91 years, which is startlingly low for a toy breed and reflects how many are bred badly and how vulnerable a dog under six pounds is to accidents and to poor care.
Temperament
Bold, loyal and entirely unaware of its size. Chihuahuas bond intensely, usually to one person, and they are famously willing to confront dogs twenty times their weight.
The common problems are behavioural and they are largely made by owners. A dog that is carried everywhere, never socialised and never asked to behave becomes reactive and snappy. A Chihuahua trained and socialised like a dog behaves like one. They are not a good match for very young children, because they are genuinely fragile.
Care and grooming
A weekly brush for the smooth coat and twice weekly for the long. Minimal work.
The health list is long for a small dog: patellar luxation, collapsing trachea, hydrocephalus, heart valve disease and severe dental disease, which affects nearly all small breeds and this one particularly. Daily tooth brushing genuinely extends life here. The moleras, a soft spot on the skull, may never close.
Living and exercise
Twenty to thirty minutes a day plus indoor play. They feel the cold badly and need a coat in winter.
A harness rather than a collar, because of the trachea. Fourteen to sixteen years is achievable with good care, and the gap between that and the 7.91 year average is mostly about how the dog is bred and kept.
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