Skinny Cats

Many cats will lose muscle mass and in some cases weight as they get older. In some cases it is a natural progression for the body type, but in other cases a medical reason can cause weight loss. It is important to make sure that your older cat is not suffering from an underlying disease if s/he is getting thinner with age. Common diseases in older cats include hyperthyroidism, kidney disease and gastrointestinal disease.

Hyperthyroidism is a disease that usually occurs in cats over 10 years of age. A benign growth on the thyroid gland excessively secretes the thyroid hormone significantly elevating the metabolic rate. These cats eat more, drink more and lose weight. They can become hyperactive and also urinate more in some cases. A simple blood test as well as palpation of the thyroid area can help determine if your cat is hyperthyroid. Treatment options include radioactive iodine which has a high success rate or medication given orally or topically that controls the thyroid level by blocking production of the hormone.  Surgery was historically a treatment, but many cats are not adequately treated with surgery.

Chronic kidney disease (CKD) occurs in many older cats. The capability of the kidneys to remove toxins from the body decreases over time and the cats will drink more and urinate more and in some cases lose weight. The word chronic is used because many cats will do well with a modified diet, monitoring of their weight and in some cases supplemental fluids. Cats can live a relatively good life for some time with a diagnosis of CKD.  Developing a close relationship with your family veterinarian, setting expectations and regular rechecks can help maximize that time and quality of life.

Gastrointestinal disease is a little more of an enigma in older cats. Older cats with weight loss may not seem to be sick at all until a significant amount of weight is lost. In many cases family veterinarians are looking for a metabolic reason for the weight loss in a blood test, but cats that have relatively normal blood tests will still lose weight. First task is to measure that cat’s calorie intake. If a cat is consuming enough calories and still losing weight, then something may be wrong with absorption or digestion of their food. These cats may need careful monitoring and discussion with your veterinarian on how to address the weight loss. In some cases these cats may need ultrasound or endoscopy and biopsies of the intestines to determine the reason for weight loss.

So, if your cat seems to be getting skinnier as it gets older there may be a medical reason and you should check with your family veterinarian to determine the cause.

Blog Post Author: 
Merrianne Burtch, DVM, DACVIM