No breed is perfect and Chihuahuas are prone to certain illnesses and disease, most treatable but some can be more serious:
Hypoglycaemia
Hypoglycaemia means low blood sugar and is a common problem in young Toy breed puppies. Symptoms of low blood sugar include glassy eyes, and lethargy. Once you know your dog has a tendency toward hypoglycaemia, you can prevent it by feeding them little and often throughout the day so that their blood sugar remains stabilised.
Collapsing trachea
Collapsing trachea is a problem for Toy dogs of many breeds. The symptoms include coughing, shortness of breath, and exhaustion. It tends to appear in the breed after the five year period and can be treated with medication successfully.
Molera
Chihuahuas (80 percent to 90 percent) have a molera — a soft spot on the top of their head similar to a human baby’s soft spot. Although it usually shrinks as the dog matures molera won’t be a problem as long as you’re gentle with this area of the head.
In rare cases, the molera remains quite large and can be a sign of a serious problem called hydrocephalus but this illness has more symptoms than just a larger than average molera.
Going under anaesthesia
The possibility that your dog may someday need anaesthesia is one main reason why your vet will need to be aware of the complications in toy breeds. Although anaesthesia-related deaths are rare, and usually the result of an allergic reaction, its use is potentially dangerous.
Be sure you get them used to regular teeth cleaning so that cleaning them under anaesthesia won’t be necessary.
Be sure your vet uses one of the modern gas anaesthetics. They are much safer than the old fashioned intravenous products.
Eye Related Problems
It’s certainly not a condition, but because Chihuahuas have big eyes and live close to the floor, where they can pick up a lot of dirt and dust, they can be more prone to eye injuries than a lot of other breeds. Put several drops of saline solution in your dog’s eye if the injury seems minor. This will flush out any small foreign objects that may have found their way to the eye. If that doesn’t relieve the problem, or if the injury appears more serious, always take them to your vet.
