Chihuahuas are the smallest breed recognised by some kennel clubs.There are two varieties of Chihuahua recognised by the AKC and the UK Kennel Club – the Smooth Coat (smooth-haired) and the Long Coat (long-haired). The AKC considers Long and Smooth coated chihuahuas to be the same breed. Contrary to popular belief, the longhaired breed also typically sheds less than its shorthaired counterparts. Up to three or more years may be needed before a full longhaired coat develops. The lifespan for a Chihuahua is usually between 12 and 20 years.Chihuahuas are also known for luxating patella, a genetic condition that can occur in all dogs.