Feline Weight Loss

Weight Loss in Cats

Overview of Feline Weight Loss

Weight loss is a physical condition that results from a cat’s negative caloric balance. This usually occurs when the cat’s body uses and/or excretes essential nutrients faster than it can consume them. Essentially more calories are being burned than are being taken in. Weight loss is considered clinically important when it exceeds 10 percent of the normal body weight and is not associated with fluid loss.

In Cats, during weight loss, the appetite may be normal, increased or decreased.

What to Watch For

Causes of Weight Loss in Cats

There are many reasons for loss of weight in cats. Some of these include:

Diagnostic Tests for Weight Loss in Cats

Confirmation of weight loss is necessary. A review of the cats former body weight(s) is essential. Once weight loss has been documented, a thorough history and physical examination, in addition to appropriate diagnostic tests are indicated to determine a cause of the weight loss. Initial diagnostic tests may include:

Treatment of Weight Loss in Cats

Your veterinarian may make several recommendations for the treatment of weight loss prior to instituting a full diagnostic work up. Such treatment is usually administered on an outpatient basis.

Home Care

Administer prescribed diets and medications precisely as directed. Periodically, weigh and record your pet’s weight. Contact your veterinarian if there is any change in body weight.

In-depth Information on Weight Loss in Cats

Weight loss is a physical condition that results from a negative caloric balance, as when metabolic utilization and excretion of essential nutrients exceed the caloric intake. Weight loss is considered clinically important when it exceeds 10 percent of the normal body weight and is not associated with fluid loss.

Weight loss can result from many different mechanisms that share the common feature of insufficient caloric intake or availability to meet metabolic needs. Causes vary markedly from intentional restriction of calories in order to reduce weight in an obese patient, to weight loss associated with life threatening illness.

Historical information is very important, especially regarding type of diet, duration and environment of storage of diet, the patient’s daily activity and, environment, the presence of pregnancy, appetite, signs of gastrointestinal disease (vomiting, diarrhea, regurgitation), or signs of any specific illness.

Causes of Weight Loss in Cats

There are several disorders or situations that need to be considered when evaluating cats for weight loss. These include:

Dietary Causes


Malabsorptive Disorders (poor intestinal absorption)

Maldigestive Disorders (inadequate break down/processing of food)

Metabolic Disorders

Excessive Nutrient Loss

Neuromuscular Diseases

Excessive Use of Calories

Chronic Infections

Diagnosis In-depth for Weight Loss in Cats

Certain diagnostic tests must be performed to reach a definitive diagnosis of an underlying cause of weight loss. A thorough work-up begins with a set of broad tests that assess the overall health of the cat. More specific diagnostics are then performed, depending on the results of the initial tests.

The following tests should be considered when working up the patient with weight loss:

Therapy In-depth for Weight Loss in Cats

Your veterinarian may recommend one or more of the diagnostic tests described above. In the meantime, treatment of the symptoms might be needed, especially if the problem is severe. The following nonspecific treatments may be applicable to some pets with weight loss. These treatments may reduce the severity or provide some relief from the symptoms. Nonspecific therapy is not a substitute, however, for definitive treatment of the underlying disease responsible for your pet’s condition.

Follow-up Care for Cats with Weight Loss

Optimal treatment for your cat requires a combination of home and professional veterinary care. Follow-up can be critical, especially if your pet does not rapidly improve, and/or continues to lose weight.

The necessity for patient monitoring and the methods required depends on the underlying cause of the weight loss; however, the patient should be weighed regularly and often.

Administer all prescribed medications as directed. Alert your veterinarian if you are experiencing problems treating your pet. If your pet is not responding, also alert your veterinarian.