Chihuahuas are rather lucky in that they a plagued with few health problems.
The three most common being Patellar Luxation, Hypoglycemia, and Hypothyroidism.

Hypoglycemia

Hypoglycemia or Low Blood Sugar can be caused by Stress, Improper Diet or Missing a Meal, Being Chilled, or to much energy being used during the day playing to long at one time. Puppies that usually are affected are the Toy Breeds, and are six weeks to 12 weeks old. The Liver stores energy, but in a small puppy it can not store enough for long periods, especially with additional stress factors. Signs of this can be as slight as a Depressed Attitude to finding your Puppy in a Coma. Treatment can be as simple as giving a small amount of Karo Syrup for a mild case to a Dextrose Solution intravenously by your Veterinarian. If you suspect this condition consult your Veterinarian for even a mild case, repeated episodes can lead to further more severe complications.

Canine Hypothyroidism

CEPS/Veterinary Extension
2938 Vet. Med. Basic Sciences Bldg.
2001 S. Lincoln Ave.
Urbana, Illinois 61802
Phone: 217/333-2907

By Joseph Hahn
Information Specialist
University of Illinois
College of Veterinary Medicine

All mammals have a thyroid gland. It is located in the neck and constantly produces thyroid hormone which speeds up metabolism. Hypothyroidism occurs when the gland stops functioning and producing thyroid hormone. It is one of the most common hormonal diseases.

“Hypothyroidism usually happens for unknown reasons,” says Dr. Leslie Henshaw, a dermatology resident and veterinarian at the University of Illinois College of Veterinary Medicine Teaching Hospital at Urbana. “Most of the other cases are caused by a destruction of the thyroid gland by the immune system.”

This disease usually affects middle-aged dogs and while it is seen frequently in Golden Retrievers, Irish Setters, and Dobermans, it can manifest in any breed.

“The first symptom that is usually seen is hair loss,” remarks Dr. Henshaw. “It is usually not associated with other skin problems.” Other symptoms may include weight gain, muscle loss, lethargy, and a tendency to seek heat (especially in winter). Pet owners usually attribute many of these symptoms to the pet’s aging process.

“This is not a life-threatening disease,” says Dr. Henshaw. “If it is left untreated however, the lethargy will get worse, the dog may experience a mental dullness, and the heart rate can slow.”

“The symptoms with hypothyroidism are usually subtle at first,” she observes. “It is a gradual process which takes months to one year to develop.”

Diagnosis of this disease is done by a series of blood tests. These tests are fairly common and can be conducted by your veterinarian.

While hypothyroidism is not a curable disease, notes Dr. Henshaw, it is very treatable. “The treatment consists of oral supplementation of the thyroid hormone on a daily basis. It is very safe, life-long, and relatively inexpensive. Treatment often rejuvenates a dog.” Many dog owners are familiar with hypothyroidism because it is a disease which also occurs in people. Although there are many similarities, owners of hypothyroid dogs should follow the advice of their veterinarian, as the dosage of thyroid hormone supplementation is very different for dogs..

Dr. Henshaw remarked that hypothyroidism can complicate other skin diseases and, if left untreated, will affect the quality of life. Once diagnosed, there are virtually no side effects from the drug therapy and there is very little monitoring needed. Once the hypothyroidism is controlled with drug therapy, a dog will no longer be predisposed to other disease conditions. Dog owners are often pleasantly surprised that their “old dog” is acting “younger.”