Chihuahua's are not only the smallest dog breed in the world, but also the oldest breed on the American continent.

Their name originates from the Mexican State of Chihuahua, after this dog was brought to Mexico from Europe in the nineteenth century.

It's original heritage is unclear but some think it originated from the Fennec Fox.

Chihuahuas were sacred to Pre-Columbian Indian nations and were also popular dogs to the wealthy & upper class.

Today Chihuahuas are prized for their size and are most valued to some fanciers if they weigh under 2.25 pounds.
• Great companion dog.
• Courageous, proud, adventurous, love affection and can be extremely lively.
• Known to be 'strong willed' if not shown the are #2 after You.
• Intelligent and with positive reinforcement training ~ learn quickly, but otherwise can be
difficult and dominant.
• If your Chihuahua becomes the 'pack leader' they can develop jealousy, aggressive behavior
with other dogs and sometimes humans.
• Known to snap at children.
• Generally NOT recommend for children.
• They require physical and mental stimulation ~so get out and 'walk' them. Don't assume they
get enough exercise in the house alone.
• Can be distrustful of others.
• Prone to colds and gum problems.
• Do not do well in cold outdoor climates, prefer warm climates.
• Can develop glaucoma due to their protruding eyes.
• Gain weight easily.
• Be cautious around toxic products such as fertilizer in the grass. Doesn't take much to poison
this little fella.
• Great apartment dogs.
• Easy to groom, bathe and travel with.

Temperament

The Chihuahua is a lively, charming, and intelligent breed. They are very devoted to their owners, though usually only choose one or two "favorites". Not only do they give affection, they in turn demand it. Their creative and curious nature drives them to create various ways to gain your attention.

Owners of more independent breeds may find the Chihuahua too needy. Households with older children are preferred, as they can be injured easily by younger children. Valued for their loyalty and courageousness, they often become "full of themselves" and will challenge much larger dogs and strangers, and because of their size this can often result in severe injuries or possibly death. They are also very suspicious of strangers (which also makes them good watchdogs), and will not let you out of their sight. It's often said they have "terrier-like" qualities... as they are very alert, observant, bold and saucy.

They are very clannish nature, meaning that they'd choose to be with other Chihuahuas, over other dogs. Some can be quite the sun-bathers, choosing to lay in the sun for hours, thought this must be closely monitored to avoid heat strokes. Their gentleness and sweet nature makes them perfect for elderly and handicapped people. Never leaving your side, they will lay in bed with you for hours on end; preferably under the covers... of which they love.

They can sometimes be overly insecure and high-strung, which can result in separation anxiety. Chihuahuas are known to bark excessively when left alone for too long. If you find yourself out of the home for long periods of time, then this is not the breed for you, as they thrive on their humans.

Chihuahuas are not recommended for being in homes with small children (unless raised with them) as they may resort to biting in self defense. Many tend to be fairly dog-aggressive. Their level of devotion to their humans can become a problem, as they are sometimes overly jealous of their humans relationships with one another and animals.

Health Problems

Common Health Problems seen in Chihuahuas are:

Patellar luxation (kneecap slips out of place)

Mitral valve heart disease
Hemophilia (genetic bleeding disorder where the blood does not clot)

hydrocephalus
hypoglycemia
eye problems
undescended testes

Epilepsy
collapsing tracheas

jawbone disorders
rheumatism fractures
Possible Dental problems
Heart Murmurs and seizure disorders.

Another problem that is seen is Cystinuria, which is when crystals (created from the amino acid, cystine) form in the urine and create kidney and bladder stones. Blood in the urine or urinating in small amounts, are indications of whether or not stones are present. This can be treated, though it is a lifelong commitment.

Mitral valve Heart disease, is caused by irregular functions of the valve separating the upper and lower chambers of the left side of the heart. Males have a 50% more likelihood of being affected than female dogs. Usually occurring in older dogs, there is no cure for Mitral valve disease, though there are some medications that may help in prolonging their life. Symptoms include: passing out, lethargy, and weakness.

**Chihuahuas are the only breed of dog not born with fully developed skulls. Usually not until 3 or 4 months of age does it finally form. Because of this, they are susceptible to hydrocephalus, or water on the brain. hydrocephalus is when the fluid, instead of being removed, builds up in the brain and enlarges the skull; usually resulting in death by 6 months of age.

Symptoms of this disease can be:
lethargy, not growing at the same rate as the rest of the litter
unusually large molera
eye abnormalities
loss of balance
even seizures.

It is not known whether or not it is congenital. A veterinarian can help determine whether it is a normal molera, or hydrocephalus. In some, a molera may never fully close and they are able lead happy, healthy lives.

They are also at risk for hypoglycemia (low glucose or sugar level). This can be fixed by leaving food out at all times, or Feeding multiple small meals throughout the day. If left unnoticed, hypoglycemia can lead to comas or even death. They may also seem to have a tendency to tremble, but this is not a Health issue; it is usually caused by stress or excitement.

Eye problems are another problem often seen in Chihuahuas, due to their large, protruding eyes. Progressive Retinal Atrophy or PRA (hereditary degenerative lesions of the retina), Generalized PRA (results in night blindness in both eyes), and Central PRA (results in day blindness are ones most often seen. Both generalized and central PRA will lead to total blindness.

Grooming

Though grooming varies between the longhaired and shorthaired Chihuahua, there is a general amount of other care that they should both receive. The teeth should be regularly checked for tarter, gum disease, and tooth decay. Dental problems are a common health problem with this breed, so keeping them clean is of utmost importance.

Also remember to pay close attention to the eyes. Use a cotton ball, dipped in a small amount of saline to clean the eye. The breed is also known to have very watery eyes, this can cause tearstains. By applying saline (or any other tearstain removal products) to the stain will help to reduce, or even eliminate ,the stains. This should be done one to two times a week depending on the level of staining.

Regarding grooming requirements, the shorthaired Chihuahua only needs an occasional brushing once or twice a week. They tend to not need as many baths as the longhaired Chihuahua.

For the longhaired Chihuahua, regular brushing with a bristle brush at least two to three times per week is needed, though daily brushing is often recommended. The bib (the long hair on the chest) should at least be brushed daily. Another area that can be a problem is the rear end, as fecal matter and other stuff can become stuck. This area is usually clipped shorter or bathed more frequently.

Exercise

Due their size, they are able to get enough exercise just running from room to room. This makes them a great apartment dog, as they do not need a lot of space to exercise in, compared to a larger dog. They should not be allowed to jump off furniture as they are very fragile and break bones easily.

Though, this does not mean that they would not enjoy a short walk on leash. This playful breed enjoys being with their owners and going on outings, though in wintertime they may require a jacket to keep warm. It's common for some owners to carry them around in soft carrier-type shoulder bags, though they are perfectly fine to walk by themselves; it also helps them stay in shape.

Because of their fragile bone structure around the neck and throat, a Y-shaped harness should be used rather than a collar.

Training

Though trained fairly easily, one difficulty with this breed is housebreaking. Because of their size, some owners will try ('try' being the operative word) training them to go on a "pee pad" or in a litter box. Paper training is never really 100%, though in some dogs it can, but rarely. In reality, your dog would forgo going on grass or other surfaces, making trips a hassle as you will need a travel pad. If you plan on staying in a hotel, or being a guest in someone's home, most people would not be very welcoming to you bringing a litter box with you. Not only do most dogs miss the pad entirely, but they will then go on any paper or pad left on the floor to do their business.

Proper housetraining should be done outside. It tends to be because of their size that most people decided to paper-train them. If one does want to only use a litter box or pad, constant praise is a MUST, each and every time they go on the pad; a pad inside of a litter box works best as its easier to clean up.

Early socialization with this breed is very important. They should be exposed to different places, people, animals and other dogs, starting at an early age. Socialization with other dogs is a major requirement as most Chihuahuas can be dog-aggressive.