Chihuahua: Breed standards for this dog do not generally specify a height, only a weight and a description of their overall proportions. As a result, height varies more than within many other breeds. Generally, the height ranges between six and ten inches. However, some dogs grow as tall as 12 to 15 inches. Both British and American breed standards state that a Chihuahua must not weigh more than six pounds for conformance competition. However, the British standard also states that a weight of two to four pounds is preferred and that if two dogs are equally good in type, the more diminutive or smaller is preferred. The Fédération Cynologique Internationale (FCI) standard calls for dogs ideally between 1.5 and 3.0 lb, although smaller ones are acceptable in the show ring. Pet-quality Chihuahuas (that is, those bred or purchased as companions rather than show dogs) often range above these weights, even above ten pounds if they have large bone structures or are allowed to become overweight.
Chihuahuas, being naturally territorial and protective, Chihuahuas can be easily provoked to attack, and are therefore generally unsuitable for homes with small children, but not in all cases. The AKC describes the breed as, "A graceful, alert, swift-moving little dog with saucy expression, compact, and with terrier-like qualities of temperament." The breed tends to be fiercely loyal to one particular owner, but may be attached to more. They do not always get along with other breeds. These traits generally make them unsuitable for households with small or boisterous children.
Chihuahuas crave attention, affection and petting. They can be hyper, but eager to please. They have a reputation as a "yippy" dog, which can be resolved with proper training. Chihuahuas with proper breeding are not "yippy"; the AKC standard calls for "a terrier-like attitude." Long haired chihuahuas tend to have a more mellow temperament.
Chihuahuas are not well-suited as small children's pets because of their size, temperament, and tendency to bite when frightened. It is recommended that children be school aged or older before adding a Chihuahua to one's home. Also, many Chihuahuas focus their devotion on one person, becoming overly jealous of that person's human relationships. This can be mitigated through socialization. Chihuahuas also tend to have a "clannish" nature, often preferring the companionship of other Chihuahuas over other dogs.
In southern California in 2009, three Chihuahuas protected their master, a three year old girl, from a 100 pound mountain lion.
This breed requires expert veterinary attention in areas such as birthing and dental care. Chihuahuas are also prone to some genetic anomalies, often neurological ones, such as epilepsy and seizure disorders.
Chihuahuas, and other toy breeds, are also prone to the sometimes painful disease, hydrocephalus. It is often diagnosed by the puppy having an abnormally large head during the first several months of life, but other symptoms are more noticeable (since "a large head" is such a broad description). Chihuahua puppies exhibiting hydrocephalus usually have patchy skull platelets rather than a solid bone, and typically are lethargic and do not grow at the same pace as their siblings. A true case of hydrocephalus can be diagnosed by a veterinarian, though the prognosis is grim.
Chihuahuas have moleras, or a soft spot in their skulls, and they are the only breed of dog to be born with an incomplete skull. The molera does fill in with age, but great care needs to be taken during the first six months until the skull is fully formed. Some moleras will not close completely over the lifespan of the dog and will require extra care to prevent injury. Many veterinarians are not familiar with Chihuahuas as a breed, and mistakenly confuse a molera with hydrocephalus. The Chihuahua Club of America has issued a statement regarding this often deadly misdiagnosis.
Chihuahuas can also be at risk for hypoglycemia, or low blood sugar. This is especially dangerous for puppies. Left unattended, hypoglycemia can lead to coma and death. This can be combated with frequent feedings (every 3 hours for very small or young puppies). Also Chihuahua owners should have a simple sugar supplement on hand to use in emergencies, such as, Nutri-Cal, Karo syrup or honey. These supplements can be rubbed on the gums and roof of the mouth to rapidly bring the blood sugar level up. Signs of hypoglycemia include: lethargy, sleepiness, low energy, uncoordinated walking, unfocused eyes and spasms of the neck muscles (or head pulling back or to the side).
Chihuahuas are also prone to eye infections or eye injury due to their large, round, protruding eyes and their relatively low ground clearance. Care should be taken to prevent visitors or children from poking the eyes. The eyes also water to remove dust or allergens that may get into the eye. Daily wiping will keep the eyes clean and prevent tear staining. Chihuahuas also have a tendency to tremble but this is not a health issue, rather it takes place when the dog is stressed, excited or cold. One reason for this may be because small dogs have a higher metabolism than larger dogs and therefore dissipate heat faster. Due to this Chihuahuas often wear coats or sweaters when outside in the cold or in overly air-conditioned places. Chihuahuas often like to dig and snuggle down in blankets for sleeping.
Although figures often vary, as with any breed, the average lifespan range for a healthy Chihuahua is approximately 10 to 17 years of age.
Chihuahuas are sometimes picky eaters, and care must be taken to provide them with adequate nutrition. Chihuahuas could earn this reputation because they seem to find small unnoticed bits of food all day. Sometimes wet or fresh food can have the most appealing smell to these constant eaters. "They will eat when they are hungry" - does not apply here as Chihuahuas are prone to hypoglycemia and could be at a critical state if allowed to go too long without a meal. At the same time, care must be exercised not to overfeed them. Human food should be avoided. Due to their small size even tiny high fat or sugary treats can result in an overweight Chihuahua. Overweight Chihuahuas are susceptible to having an increased rate of joint injuries, tracheal collapse, chronic bronchitis, and shortened life span.
