Why Is My Cat Losing Weight? 10 important Reasons why your cat is losing weight?

This post include on query Why Is My Cat Losing Weight? what could be the reasons that your cat is losing weight progressivley here are legit reasons about why has my cat lost weight day by day by thevetscare.com


Veterinarian examining cat in vet's surgery
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Is your cat is losing weight? Unintended weight loss is usually a sign of an underlying health problem. Many owners think that weight loss is normal for senior cats, but this is not the case. It’s important to take action if you notice unexplained weight loss in your cat.

Why Is My Cat Losing Weight?

How to Tell if Your Cat is Losing Weight

It is hard to tell if your cat is really losing weight if it happens gradually. If your cat has a lot of hair or used to be slightly overweight, then it can be harder to tell when weight loss has occurred.

To assess your cat’s body condition, start by looking at your cat’s body from above. At an ideal weight, there should be a tuck at the waist that is noticeable but not extreme. Next, run your hands along your cat’s sides. The ribs should be palpable with a thin covering of fat. If the ribs feel very prominent and are visible, your cat is likely underweight.

What Causes Cats to Lose Weight?

In many cases, cats lose weight when they are not eating enough. However, some diseases cause weight loss despite adequate food intake. Depending on the cause, weight loss may or may not accompany other signs of illness. Many health problems can cause weight loss in cats, some more serious than others.


Hyperthyroidism is a relatively common illness that most often affects older cats. Cats with hyperthyroidism produce too much thyroid hormone due to an enlargement of the thyroid gland. This enlargement is usually caused by a benign tumor that grows on the thyroid.

Common signs of hyperthyroidism include weight loss, increased appetite, and increased thirst and urination. Some cats also experience vomiting, diarrhea, and hyperactivity. Some will vocalize and act restless. Cats with hyperthyroidism may have coats that appear unkempt and greasy. Hyperthyroidism is treated with radioactive iodine or oral medications.

Chronic Kidney Disease

Chronic kidney disease is one of the most common illnesses seen in senior cats. The kidneys produce important hormones, filter out wastes from the blood, help regulate blood pressure, and facilitate the production of new red blood cells. When a cat’s kidneys stop functioning properly, it leads to a variety of other issues.

Increased thirst and urination are among the first signs noticed when a cat has kidney issues, followed by loss of appetite, weight loss, and lethargy. Chronic kidney disease cannot be cured, often be medically managed with medication, diet change, and fluid supplementation.


Diabetes mellitus is another common ailment that can affect cats. This endocrine disorder affects the ability of the pancreas to produce insulin, a hormone needed to regulate blood glucose.

Signs of diabetes include weight loss, increased appetite, thirst, and urination, and lethargy. Diabetes is typically managed with insulin and a diet change. Other medications may be used. Some cats will even revert back to normal after several months of treatment.

Gastrointestinal Problems

Any issue in the GI tract can affect a cat’s weight. First, GI problems can reduce appetite. Second, some issues prevent the GI tract from properly digesting food and absorbing nutrients, leading to weight loss. Some GI problems seen in cats include intestinal parasitesinflammatory bowel diseasepancreatitis, and other pancreatic issues, and even cancers of the GI tract.

GI issues may cause loss of appetite, weight loss, vomiting, diarrhea, lethargy, and more. Treatment of GI parasites may be as simple as deworming the cat. Other GI issues typically require medications and supportive care.

Dental Problems

Oral and dental issues can cause extreme pain, decreasing appetite and leading to weight loss. Common dental problems in cats include periodontal disease, resorptive lesions, and tooth fractures. Some cats develop stomatitis, a painful inflammation of a cat’s mouth and gums that may be immune-mediated.

Signs of dental issues include bad breath, drooling, pawing at the mouth, or even oral bleeding. The first step to treatment is for the vet to put your cat under anesthesia and do a professional dental cleaning, exam, and treatment as necessary. Some cats will need oral surgery and/or tooth extractions.


Like people, cats can get cancer just about anywhere in their body. Cancer may or may not be seen in the form of a tumor. Lymphoma is one of the common cancers seen in cats and it can live in the GI tract, mouth, lymphatic system, and more. Most forms of cancer will eventually cause general malaise, lethargy, pain, muscle wasting, appetite loss, and overall weight loss.


Cats can be very sensitive to changes in their home. Because they are often excellent at hiding outward signs of stress, they can experience bigger symptoms later on. Any environmental stressors can lead to anxiety and stress in your cat. Reduced appetite is a common sign of stress and will eventually lead to weight loss.

There are a number of other health issues that can lead to weight loss. If your cat has an underlying health issue, you may or may not notice other signs of illness. In addition, many diseases have similar symptoms, so diagnosis requires a veterinarian.

Treatment for Weight Loss in Cats

The treatment for weight loss in cats depends on the cause. If you notice your cat is losing weight, your first step should be to schedule a vet appointment. Your vet will do a physical exam first. Next, lab tests and/or x-rays may be needed to determine the problem. Based on the findings, your vet may recommend medication, diet change, surgery, or other treatment.

If your vet gives your cat a clean bill of health, then the weight loss may be caused by inadequate food intake or some unknown or undetectable condition. Ask your vet for advice about feeding and environmental enrichment. If you can determine a source of stress for your cat, start by working to reduce that stress. Your vet can also recommend a diet that is right in nutrients and calories, potentially helping your cat gain weight.

If your cat’s weight loss continues despite changes you make, then make sure to follow up with your vet about it. Your vet may refer you to a veterinary specialist for advanced diagnostics.

How to Prevent Weight Loss in Cats

You can prevent weight loss in your cat by regularly monitoring body condition and visiting the vet regularly for wellness examinations. Cats are experts at hiding illness and injuries, but your vet may be able to detect a problem before it gets out of hand. Be sure to report any changes in your cat’s behavior to your vet right away. It is much easier to treat a health problem in the early stages than to wait until your cat becomes very ill.

Many people worry about their cats getting fat, but unintentional weight loss can be a serious issue, too. It may be a sign of an underlying medical problem.

Depending on the reason for your cat’s weight loss, you may notice that your cat’s appetite is reduced or entirely gone, a condition known as anorexia. This is dangerous for cats, because they are prone to something called hepatic lipidosis, or fatty liver syndrome, a life-threatening condition that can develop when the liver must process large amounts of stored fat to provide energy to the body.

But there are other medical situations that will cause your cat to lose weight, even if she continues to eat her normal amount of food.

Whether your cat is eating or not, if you notice your cat is losing weight, it is important to consult your veterinarian. If you are not sure what your cat’s ideal weight should be, your veterinarian will be able to provide guidance and a suggested feeding regimen to meet your cat’s nutritional needs.

Why my older cat is losing weight?

Causes of Cat Weight Loss

Anxiety, stress, or depression. Cats under psychological stress may go off their food, which can result in weight loss. Situations that may upset your cat include excessive noise, other animals in the feeding area, dirty food dishes, or proximity of the food dish to the litter box. Cats can also be upset by the disappearance of another pet or by a change in a routine.

Cancer. Although not all cat weight loss is caused by cancer, it is a relatively common culprit. Other symptoms that commonly appear include loss of appetite, lethargy, and hiding.

Diabetes. This disease, which may be caused by a failure to produce the hormone insulin or an impaired ability to respond to it, commonly causes weight loss in cats, often with a change in appetite. Cats with diabetes may also drink excessive amounts of water, urinate more than usual, act sluggish, develop urinary tract infections, and have sweetly scented breath.

Feline infectious peritonitis. This virus, which most commonly occurs in cats raised in catteries, is known to cause wasting. Cats with FIP will seem sick, often with a fever that doesn’t respond to antibiotics.

Gastrointestinal problems. There are a variety of different conditions in the gastrointestinal tract that may cause cat weight loss. When this is the case, other symptoms may include diarrhea, lack of appetite, and vomiting. Common GI problems that produce weight loss in cats include inflammatory bowel disease, food allergies, or certain infections.

Intestinal parasites. Also known as worms, intestinal parasites may be the cause of your cat’s unintentional weight loss. Although symptoms are not always present, these parasites also may cause diarrhea, bloating, vomiting, and trouble breathing.

Organ failure. Many elderly cats exhibit weight loss, and it can be difficult to determine the precise cause of the problem, especially because metabolism changes with age. Conditions such as kidney disease become more common as cats get older. Your veterinarian can identify these problems with simple blood and urine tests.

Hyperthyroidism. Your cat may have a good appetite; in fact, she may be eating more than usual but is still losing weight. Hyperthyroidism results from a benign hormone-producing tumor on the thyroid gland that elevates levels of thyroid hormone. In addition to weight loss, hyperthyroidism may cause increased drinking and urination, increased activity, vomiting, diarrhea, and muscle wasting. In later stages, it may even lead to heart problems or death. Older cats also are particularly prone to developing this condition.

Toothache. If your cat suddenly stops eating and begins to lose weight, but seems otherwise healthy, it could be something as simple as a sore tooth causing the problem. Drooling and pawing at the mouth may be other signs of a tooth issue. Mouth ulcers or severe gingivitis can also contribute to the problem.

Treatment and Home Care for Underweight Cats

To determine what is causing your cat’s weight loss and design the best treatment plan for you and your pet, your veterinarian will likely do a complete physical exam, blood work, and urinalysis.

Depending on the reason for your cat’s weight loss, a variety of treatments and dietary changes to treat the underlying condition and restore weight may be prescribed. Fortunately, even in older cats, weight loss can often be treated, if not cured.

The weight loss caused by certain conditions of the gastrointestinal tract may be addressed, either solely or in part, by making appropriate changes to your cat’s diet. If your cat is suffering from inflammatory bowel disease or other conditions that make food absorption difficult, an easily digested diet may be recommended. Cats that lose weight because of food allergies may recover completely when the offending foods are removed from their diet.

In situations where lack of appetite is contributing to weight loss, appetite-stimulating medications or feeding tubes may be used to maintain adequate nutrition while the cause of anorexia is being addressed.