The thyroid gland is a small gland located in the neck. It very important role in regulating the body's rate of metabism, or what "speed" the body is running. Middle age dogs sometimes have a thyroid gland that is UNDERACTIVE causing a slow metabolism. This condition is called canine hypo-thyroidism. Older cats can get just the opposite problem. Their thyroid gland can become OVERACTIVE and cause metabolism to be too fast, called feline hyperthyroidism.

Canine Hypothyroidism: Your dog may be overweight for a reason!

An underactive thyroid gland will cause your dog to slow down in many ways. Hypothyroid dogs are often obese. They gain weight even on a restricted diet. They may sleep more and have reduced stamina. They seek out warm places to nap and have an overall reduced tolerance to the cold weather. They often have dry, flakey skin and a dull haircoat. They may have areas of hair loss and recurrent skin and ear infections. Breeding dogs may have a lack of libido and females may stop cycling altogether. On examination, hypothyroid dogs often symptoms of this disease can be treated very successfully with medication given once or twice a day. Owners will usually see an overall improvement in their dog's health within 2 to 4 weeks.

Feline Hyperthyroidism: Your cat may be losing weight for a reason!

Hyperthyroidism is a fairly common disease of older cats. It is caused by a benign tumor on the cat's thyroid gland. The result is the exact opposite of the symptoms described above for a hypothyroid dog. The most common finding is weight loss despite a ravenous appetite. Affected cats also drink a lot of water and urinate a lot. They may vomit and have more frequent bowel movements, and they may make mistakes outside the box. They may seem restless and vocalize more than usual, and they may neglect normal grooming. They seek cool places to lie because their overall body temperature is too high. Hyperthyroid cats may develop a rapid heart rate, which can create serious problems. High blood pressure develops as a consequence of increased pumping by the heart. In some cats blood pressure can become high enough to cause blindness. Heart failure can develop as the heart enlarges and thickens to meet the increased metabolic demands.

Just like with dogs, a blood test can confirm this thyroid condition. A medication can control the effects of the overactive thyroid gland. If your cat is resistant to taking the medication, other options are available. The problem can be completely cured by having the benign tumor on the gland irradiated or surgically removed.