Chihuahua

The Chihuahua (also called the Chihuahueño) is a Mexican breed of toy dog and the smallest recognised dog breed in the world. It is kept mainly as a companion and is known for its compact size, large erect ears and rounded skull.

The Chihuahua comes in short-coated and long-coated varieties, in almost any colour or pattern, from solid to marked or splashed. Apple-dome Chihuahuas have large, round eyes and a well-defined stop, where the muzzle meets the skull at close to a right angle.

Height is usually about 15 to 23 cm (6 to 9 in), though some grow to 30 to 38 cm (12 to 15 in). Breed standards mostly describe weight rather than height. The British standard prefers 1.8 to 2.7 kg (4 to 6 lb), while many pet Chihuahuas weigh more, sometimes over 4.5 kg (9.9 lb).

Genetic studies suggest native American dogs reached North America from Siberia around 10,000 years ago and were then isolated for about 9,000 years until Europeans arrived. Their distinctive genetic signature is now nearly extinct. A 2020 ancient-genome study found about 4% of this pre-colonial ancestry in the Chihuahua, while an earlier 2013 study had suggested it might be as high as 70%.

Colonial records mention small, nearly hairless dogs from the early 19th century, and one account claims 16th-century conquistadores found them plentiful in the region later called Chihuahua. In 1520, Hernan Cortés wrote that the Aztecs raised and sold little dogs as food.

The American Kennel Club first registered a Chihuahua in 1904, a dog called Midget owned by H. Raynor of Texas. The breed has since become one of the most popular companion dogs worldwide.

Like many small dogs, the Chihuahua may show above-average aggression toward people and other dogs. The American Kennel Club does not recommend the breed for families with young children.

Chihuahuas tend to be mildly good with other dogs, though this varies with the breed of the other dog.

They also have a molera, a soft spot on the head much like the fontanel in human babies. It can be hard to see but is easy to feel.

The Chihuahua has a genetic predisposition to several neurological conditions, including atlantoaxial instability, ceroid lipofuscinosis, congenital deafness, congenital hydrocephalus, muscular dystrophy, necrotizing meningoencephalitis and neuroaxonal dystrophy. It has a mild predisposition to congenital heart disease, and its predisposition to medial patellar luxation is believed to be significant. In one study of dental disease, the breed had the lowest incidence of the six breeds studied.

Puppies of toy breeds are susceptible to low blood sugar (hypoglycaemia), often as a result of low body temperature. Difficult birth is also a concern: a UK study found obstructed labour was 10.4 times more common in Chihuahua females than the average for all dogs.

Life expectancy figures vary by study. A 2024 UK study found 11.8 years, while a 2022 UK study based on veterinary data found 7.91 years. A Japanese study found 11.8 years and an Italian study 8.5 years.

This is general awareness only, not veterinary advice. Always consult a vet about your pet's health.

How big do Chihuahuas get?

Most stand about 15 to 23 cm (6 to 9 in) tall, and some reach 30 to 38 cm. Show standards set preferred weight ranges, but many pet Chihuahuas weigh more than the standard, sometimes over 4.5 kg, and are still purebred.

How long do Chihuahuas live?

Studies give different figures. A 2024 UK study found an average of 11.8 years, compared with 12 years for crossbreeds. Other studies found averages ranging from 7.91 to 11.8 years.

Are Chihuahuas good with children?

The American Kennel Club does not recommend them for families with young children. The breed may also show above-average aggression toward people and other dogs.

What is the soft spot on a Chihuahua's head?

It is called the molera, and is much like the fontanel in human infants. It is hard to see but easy to feel.

What is a teacup Chihuahua?

Teacup or tiny teacup is a marketing term for very small Chihuahuas, which command higher prices. Chihuahuas do not breed true for size, so puppies in one litter can grow to very different sizes.

The Chihuahua keeps a small share of pre-Columbian American dog ancestry, which sets it apart from most modern breeds that are largely of European origin.

An older deer type has a flat-topped head, wider-set eyes, larger ears and longer, slimmer legs. It may still be registered, but it is not counted as a separate type in competition.

The Kennel Club of Great Britain amended its standard in 2007 to disqualify the merle coat pattern because of health risks linked to the underlying gene.