Your Chihuahua is also at greater risk of suffering from additional diseases or conditions that can severely impair her health. Several conditions are unique in that they appear during the puppy's first year.

The most common health issues that Chi puppies are susceptible to include water on the brain (hydrocephalus); juvenile hypoglycemia (a drastic drop in blood sugar levels); cryptorchidism (one or both testicles do not descend); and shark teeth (puppy's milk teeth do not fall out and adult teeth erupt and grow in beside them).

Hydrocephalus and juvenile hypoglycemia are both lifethreatening conditions that must be attended to immediately. All Chihuahua owners should be on the lookout for these conditions and should be equipped and prepared to handle an emergency while on the way to the veterinarian for additional critical care.

Hydrocephalus

Hydrocephalus is commonly confused with the presence of a molera, or soft spot on the Chihuahua's head. The two are not related. Hydrocephalus is the collection of cerebrospinal fluid (the fluid in and around the puppy's brain). As fluid collects, more and more pressure is applied to the brain. In severe cases, the puppy dies within a matter of days. In moderate cases, the fluid collection may take months before symptoms begin to appear, and in very slight cases, the pup may not show any signs of the condition until much later in life.

Symptoms of hydrocephalus include the following:

Domed skull that becomes more pronounced over time

Failure to thrive

Abnormal movements

Odd behaviors

Vision impairment

Seizures

Difficulties learning (impossible to housetrain, slow with obedience, and so on)

For most Chihuahuas, if the fluid pressure on the brain can be minimized quickly either through surgery (placement of a permanent drainage shunt) or medications (corticosteroids), the condition usually stabilizes by the age of two. These Chis, however, almost always suffer brain damage, and in some cases your veterinarian may recommend euthanasia.

Hypoglycemia

Puppies of all toy breeds can have difficulties maintaining a high enough level of sugar in their blood. The Chi's body's response to low blood sugar is very much like a diabetic suffering from the same condition: anxiety, dizziness, disorientation, trembling, a racing heart beat, seizures, and collapse.

To help prevent a pup from becoming hypoglycemic, feed your Chi many small meals throughout the day, and make sure that the puppy has actually eaten what you've given her. Additionally, keep a small container of honey in the home to rub on her gums if she appears to be suffering from low blood sugar. As always, seek advice from your veterinarian. The symptoms of hypoglycemia are similar to other diseases, and the problem may not be your puppy's diet at all.

A Case of Too Little or Too Much

Two other puppy problems include too many teeth and not enough private parts. Chihuahua puppies on occasion retain their deciduous or baby teeth. The adult teeth erupt and grow in, giving the Chi a sharkish appearance. In addition to looking a bit odd, it is important to have the baby teeth removed by your veterinarian. Retention of these teeth leads to trouble, not the least including food that gets caught between two sets of teeth and increases a Chi's chances of developing tooth and gum disease.

Cryptorchidism is the term given to undescended testicles. All male puppies begin with testicles in their body cavity, which usually descend by the time the puppy is six to eight weeks. This process can take up to twelve weeks in some cases. If a male Chi puppy has one or both testicles that refuse to descend, it is critical that you have the puppy neutered and the testicles removed. Male Chis with undescended testicles are at far greater risk for cancer. Since this trait is hereditary, these dogs should never be bred.