Diagnosis Important in Determining Cause of Cat’s Weight Loss

If your cat has been losing weight and condition it is time for
a consultation and exam by your veterinarian. There can be many
reasons for weight loss in cats. Age alone is not one of them.
If your cat has been losing weight and condition it is time for a consultation and exam by your veterinarian. There can be many reasons for weight loss in cats. Age alone is not one of them.

Behavioral, degenerative, infectious, cancer, metabolic and hormonal reasons are the ones that your veterinarian will consider.

Behavioral reasons might be seemingly simple changes in your cats’ environment. Cats are extremely territorial and often react to changes in relatively extreme ways. A new animal, such as another cat or a dog, can interfere with your cats’ access to the food dish. It is surprising how often a lively puppy will unwittingly create a blockade between a cat and its food. Between cats a simple glance can be an aggressive act once dominance is established or challenged. A new baby in the family can also change the territorial map of the household in ways that are poorly understood by humans.

Degenerative diseases can include arthritis, asthma and cardiac-based problems as well as digestive problems. The pain of arthritis can make it difficult for your cat to get to previously easily accessible food sources. Asthma and degenerative heart diseases can affect weight in several ways. Activity and the ability to access certain locations may be impacted. The ability to digest, absorb and utilize nutrients may be diminished due to poor oxygen delivery to the body and its cells. Impaired oxygen delivery from any cause will damage the ability of the body to maintain itself in a normal way. All these diseases will also ultimately lead to loss of muscle mass and body condition through diminished activity.

Inflammatory Bowel Disease (like colitis in people) can cause chronic vomiting and/or diarrhea and frequently results in weight and condition loss. Diagnosis requires lab testing and endoscopy of the gastrointestinal system. It can be treated with inexpensive medications

Infectious causes include contagious diseases and infected injuries. Feline Leukemia Virus, Feline Immunodeficiency Virus (both in the same family as HIV in humans), Feline Infectious Peritonitis (FIP), Feline Distemper Virus, Calici Virus and fungal infections are just a few samples of the contagious diseases your veterinarian will be considering. There are too many to catalogue in this article. The point is that there is a large catalogue of potential problems that are beyond the scope of knowledge of the average cat owner. Among the history, physical exam and laboratory testing, many problems can be ruled in or out.

One of the most common infections is an abscess resulting from cat fights. Abscesses are not always obvious to the owner. They can drain and then reform, causing chronic stress and loss of appetite. They can also occur inside the body, especially inside the chest, where the only signs may be lethargy and loss of appetite – leading to loss of condition.

Intestinal parasites are another form of infection that can lead to weight and condition loss. The good news here is that Interceptor, a chewable heartworm preventive, also kills most intestinal parasites and their larvae. Unlike Heartgard Plus, Interceptor is licensed for use in cats. It is very safe, is relatively easily to administer and a year’s supply costs about the same as an annual stool check and worming.

Cancer is often not obvious. Lymphoma, sometimes associated with Feline Leukemia Virus infection, can often require X-rays for diagnosis. Other tumors may affect your cat’s ability to smell food. Something most cat owners are not aware of is that cats are odor eaters. Their appetite is driven much more by odor than by taste. Anything that causes loss of acuity of smell can result in loss of appetite and the consequent loss of body condition.

Other ways that cancer can affect body condition are by causing pain, inability to digest and absorb nutrients and by the depletion of nutrients. Cancer cells are more metabolically active than other cells. They will be first in line to take nutrition from the blood stream, often robbing normal cells of needed nutrition.

Metabolic reasons for weight loss include liver disease, kidney failure and pancreatitis. Kidney failure is one of the most common diseases of older cats. It is often not noticed until weight and condition loss occur, although increases in water drinking and urination are also symptomatic. Pancreatitis used to be considered highly unlikely in cats but better tests have changed that assumption .

A very fat cat (more than 30 percent overweight) that goes off food for as little as three days can easily develop a metabolic liver disease called hepatic lipidosis. In this disease the liver is effectively replaced by fat. Sixty percent of cats who develop this ailment die from it regardless of specialized hospital care.

The two most common hormonal reasons for weight and condition loss in cats are sugar diabetes and hyperthyroidism. These typically occur in middle to late life. They can be relatively easily diagnosed and both require a lifetime of treatment and monitoring.

It is important to understand that age alone is not a common reason for weight and condition loss. Investing in the time and cost of a veterinary diagnosis can often result in a longer, happier, healthier life for your pet and the rewards of a continued relationship for both of you.

Dr. Quick has owned and operated the Animal Care Center in Morgan Hill for 25 years. He is a founder of both W.E.R.C. and Furry Friends Foundation and was the Morgan Hill Male Citizen of the Year in 2003.