The Chihuahua doesn’t have any major health problems, but like all breeds he can be born with or acquire certain conditions. Not all Chihuahuas will get any or all of these diseases, but it’s important to be aware of them so you can be informed when you interview breeders and can know what to look for throughout your Chihuahua’s life.
Buying from a responsible breeder will help ensure that you get the healthiest Chihuahua possible. A puppy from a reputable Chihuahua breeder will be vaccinated and dewormed before you take him home. Responsible breeders use only physically sound, mature (at least 2 years or older) dogs, and test their breeding stock for genetic diseases pertinent to the breed, such as luxating patellas (bum knees) and heart disease.
Both parents should have health clearances, documentation that a dog has been tested for and cleared of a particular condition. In Chihuahuas, you should expect to see health clearances from the Orthopedic Foundation for Animals (OFA) for patellas and heart disease. You can confirm health clearances by checking the OFA web site (offa.org).
Health clearances are not issued to dogs younger than 2 years of age. That’s because some health problems don’t appear until a dog reaches full maturity. For this reason, it’s often recommended that dogs not be bred until they are two or three years old. The following conditions may affect Chihuahuas:
- Patellar Luxation: Also known as “slipped stifles,” this is a common problem in small dogs. It is caused when the patella, which has three parts-the femur (thigh bone), patella (knee cap), and tibia (calf)-is not properly lined up. This causes lameness in the leg or an abnormal gait, sort of like a skip or a hop. It is a condition that is present at birth although the actual misalignment or luxation does not always occur until much later. The rubbing caused by patellar luxation can lead to arthritis, a degenerative joint disease. There are four grades of patellar luxation, ranging from grade I, an occasional luxation causing temporary lameness in the joint, to grade IV, in which the turning of the tibia is severe and the patella cannot be realigned manually. This gives the dog a bowlegged appearance. Severe grades of patellar luxation may require surgical repair.
- Hypoglycemia: Hypoglycemia, or low blood sugar, is a possible problem with all toy breed puppies. [Note: I have left this as toy breed here. There is a difference between toy size and small dogs-the difference, say, between Chihuahuas and yorkies and beagles and mini dachshunds.] Hypoglycemia is easily treatable in the early stages but can be fatal if not treated. It is important that breeders and owners of toy breed puppies recognize the signs and symptoms because this condition can sometimes be misdiagnosed as viral hepatitis or encephalitis by veterinarians. A puppy with hypoglycemia will slow down and become listless, followed by trembling or shivering. Place some honey under his tongue and get him to the vet immediately. If the situation is allowed to continue, he’ll eventually collapse, go into convulsions, fall into a coma, and die. Any time your Chihuahua is limp, with grayish-blue gums and tongue, it’s an emergency. Hypoglycemia occurs in toy puppies when they don’t have the fat reserves to supply adequate glucose in times of stress or when they don’t eat regularly.
- Heart Murmurs: Heart murmurs are caused by adisturbance in the blood flow through the chambers of the heart. They’re an indicator that there may be a disease or condition of the heart that will need to be monitored and treated. Heart murmurs are graded on their loudness, with one being very soft and five being very loud. If disease is evident, as diagnosed through x-rays and an echocardiogram, the dog may require medication, a special diet, and a reduction in the amount of exercise he gets.
- Pulmonic Stenosis: This congenital heart disease occurs when blood doesn’t flow properly through the heart because the pulmonic valve is malformed, causing an obstruction. This means the heart must work harder and can become enlarged, leading to heart failure. Treatment depends on the severity of the disease. In mild cases, there’s little or no obstruction and no treatment is necessary. If the dog is severely affected by the disease, surgery is recommended, but the procedure differs depending on the location of the blockage.
- Collapsed Trachea: It is not completely understood how this occurs, but the rapid inhalation of air causes the trachea to flatten and makes it difficult for air to enter the lungs, much like a soda straw being drawn on too vigorously. This condition may be inherited; it occurs in certain breeds, and dogs with it show an abnormality in the chemical makeup of their tracheal rings in which the rings lose their stiffness and become unable to retain their circular shape.
- Hydrocephalus: Cerebrospinal fluid (CSF) can accumulate in the brain because of a congenital defect, obstruction, or the result of trauma during birth, placing pressure on the brain. The head looks swollen or enlarged, but the diagnosis can be confirmed with an ultrasound if necessary. There’s no cure for hydrocephalus, although in mild cases steroids can help reduce fluid pressure. A shunt can also be used to divert fluid from the brain to the abdomen. Puppies with severe cases usually die before they’re four months old, which is a good reason to delay purchasing a Chihuahua until that age.
- Open Fontanel: Chihuahuas are born with a soft spot on the top of their head. Usually the soft spot closes, much like a baby’s will, but sometimes one will not close fully. Treat these dogs gingerly. An accidental blow to the head can kill them.
- Shivering: Shivering is a common occurrence in Chihuahuas. The mechanics of why they shiver or tremble is unclear but it usually occurs when the dog is excited, stressed, or cold.