Chihuahuas are the world’s smallest dog breed with a well distinguishable apple-shaped head. The breed can be found in any color – solid, marked or splashed, and the coat can be either long or short. The breed has been named on the Mexican State of Chihuahua, where the early specimens of this breed were discovered. As against to their size, they are smart and alert dogs with the qualities of a terrier. This breed of dogs is loyal and become attached to their owners but tends to become snappish, yappy and protective against absolute strangers. They are not very comfortable in cold temperatures. Chihuahuas have a long life expectancy close to 17 years, but they are susceptible to develop health problems like hypoglycemia, joint ailments, eye infections and bronchitis. Also, the top part of their skulls never develops fully, leaving soft spots (“moleras”) that needs to be protected. They suffer from diseases like rheumatism, slipped stifle, colds, and gum problems, corneal dryness and secondary glaucoma. They should be kept safe distance from even minutely toxic products such as chocolate or fertilizer as it is a very small breed and these could prove poisonous to them. Chihuahuas are often born via caesarean section because their heads are quite large in size.