Why has my cat become so Skinny?
Cat Health and Wellness

Cat Getting Skinny But Still Eating – What Should I Do to Help?

Is your cat getting skinny but still eating? Weight loss in old cats is common, which is why pet owners with elderly cats don’t often realize that weight loss can be an indication of an underlying disease. And this can still be true if your cat is still dropping weight, but their food consumption hasn’t changed.

With cats, the loss of one pound in a ten-pound cat is huge. It’s basically a ten percent loss of total body weight, which is excessive. If your old cat seems to be wasting away, then it’s important to make an appointment with your vet before they lose more weight and begin to show other signs of illness.

Stress and it’s Relation to Weight Loss in Cats

There are several potential causes of weight loss in old cats, both non-pathological and pathological. Triggers that are non-pathological usually involves environmental stressors.

If you’ve recently added a new dog or cat, your aging feline may perceive the new animal as a threat. Or, maybe you’ve spent less time at home or changed your work schedule, resulting in less time with your cat or a change in the times your cat is fed. 

Other stressors that can affect a cat’s eating habits include meal-time competition. This can occur when all the pets in the home are fed at the same time. A cat usually feels more comfortable when they’re able to eat in private. 

Even small changes to a cat’s environment or routine can be considered a potential stressor. Because of this, it’s a good idea to try and pinpoint what could be causing increased anxiety in your pet. 

Weight Loss and Disease

A disease is more common in aging cats than younger cats. This can include kidney disease, GI disease, endocrine disorders, respiratory disease, and heart disease. 

Heart Disease in Cats 

heart problems and weight loss in cats

Heart disease in cats is a result of damage to the heart structure, which can occur over a long period of time. The most common type being cardiomyopathy. This accounts for 2/3 of feline heart conditions.

This heart condition involves a type of structural abnormality in the muscles that are surrounding both or just one of the heart chambers. The result is a scarred, dilated, thickened left ventricle. 

This type of heart abnormality will often interfere with the heart’s ability to pump blood, leading to fluid around or in the lungs, and congestive heart failure. Other complications linked to this condition include sudden death and blood clots that result in paralysis. 

While it’s believed that cardiomyopathy is caused by lifestyle and genetics, occasionally this condition can develop secondary to other disorders such as hypertension, hyperthyroidism, and anemia.

There are a few types of heart disease that can account for almost all cardiomyopathies in cats: dilated cardiomyopathy, restrictive cardiomyopathy, and hypertrophic cardiomyopathy. 

Respiratory Problems 

Chronic sinusitis or an upper respiratory infection will interfere with a cat’s sense of smell. This often affects their appetite, resulting in weight loss. 

Feline asthma can also lead to weight loss in elderly cats. Primary tumors or tissue growth of the lung can also result in weight loss, in addition to trouble breathing and lethargy. 

Endocrine Diseases 

The most common endocrine diseases that affect old cats are diabetes and hyperthyroidism. Over the past thirty years, hypothyroidism in felines has increased dramatically, in fact, ten percent of cats over the age of ten are diagnosed with this disease. 

About fifty percent of felines that develop overactive thyroids have an increased appetite, yet only ninety percent of those cats lose weight due to the side effects of too much thyroid hormone, which causes the metabolism to speed up. Other symptoms can include increased body temperature, respiration and heart rate, frequent vomiting, and high blood pressure. 

Old Cat Losing Weight and Drinking Lots of Water

Is your old cat losing weight and drinking lots of water? Diabetes in felines is the result of the pancreas not releasing enough insulin, in conjunction with an inadequate response of the body’s cells to insulin. 

The body will begin to break down protein and fat stores to utilize as fuel since the sugar in the bloodstream is unable to get into the cells of the body. The result? Regardless of how much a diabetic cat eats, they will continue to lose weight. 

Specific signs and symptoms are commonly seen in cats with diabetes. However, many of these signs can also be caused by other conditions and diseases. Because of this, lab tests are needed to diagnose diabetes. 

Depending on the severity of the disease, your cat may only show one or two symptoms, or the symptoms may be severe. While a dog with diabetes commonly develops cataracts, felines do not. 

Common signs of diabetes in felines include the following:

  • Excessive thirst
  • Increased urination
  • Weight loss 
  • Change in appetite
  • Excessive vocalization
  • Inappropriate elimination  
  • Change in ambulation 
  • Vomiting
  • Increased weakness
  • Depression 

By far, an increase in thirst is the most common symptom of diabetes in cats. So, if you notice your old cat drinking lots of water and losing weight, there is a good chance a diabetes diagnosis is in their future. 

Because sugar is not able to enter the cells in the blood, glucose levels in the blood are elevated. The glucose is filtered via the kidneys and can be found in the urine. When the sugar is filtered out, water is carried with it. The result is excessive thirst since the cat is losing more water through their urine than usual. 

Litter Box Accidents 

How to avoid litter box accidents

The increase in urination can result in your feline not always making it to the litter box in time. This type of inappropriate elimination is another common sign associated with diabetes. Additionally, a cat with diabetes will commonly develop UTIs, which can also cause inappropriate elimination. 

Appetite Changes 

Because they don’t feel well, some diabetic cats will eat less, while others may experience an increase in appetite and eat a lot more because their hypothalamus gland tells them they’re hungry. 

Unusual Gait

Some felines diagnosed with diabetes also develop nervous system abnormalities. This can result in a change in gait, such as walking with their hocks touching the ground. 

Depression and an Increase in Weakness 

Even if your cat is eating a lot of calories, their body is unable to use them efficiently. Whether a diabetic cat eats or not, they will usually always feel hungry. Some felines can lose a significant amount of lean muscle mass.

The loss of muscle mass can cause increased weakness. A cat with this condition can also feel lethargic or depressed. They often stop grooming themselves and lose interest in their surroundings. As the condition progresses, they tend to become more depressed. 

Cat Losing Weight and Throwing Up 

Is your cat losing weight and throwing up daily? A cat with diabetes may suffer from chronic vomiting episodes that are caused by waste products called ketones. If ketones build up in the system because the cat’s body is breaking down fat for energy, nausea and vomiting can occur. This effect of built-up ketones can be life-threatening. 

As their condition progresses, the cat can also develop liver disease and begin losing their fur. They can also be more susceptible to infections. 

If your cat is vomiting, and you have yet to pinpoint the cause, whether it’s diabetes or another type of serious condition, you need to change their diet. 

An older cat doesn’t require the same amount of protein he or she once did in their heyday. 

Switch to an age-appropriate option such as senior specific cat food. This type of cat food has a lower protein content and will focus on providing essential amino acids, and the vitamins and minerals aging pets need to thrive. 

Diabetes Diagnosis

Diagnosis is based on the presence of high blood glucose levels even when the animal has fasted for several hours, in addition to glucose found in the urine. These signs alone may not be enough to diagnose diabetes since renal failure, and an overactive thyroid can have similar signs. 

To get an accurate diagnosis for your aging cat, you’ll need to discuss your cat’s medical history, including the duration, onset, and severity of the signs we have discussed here. This can be very important in determining the correct diagnosis. 

A physical exam is also needed. A vet may find poor grooming habits, dehydration, depression, and weight loss, as well as enlarged kidneys or an enlarged liver. 

Lab Tests 

As we’ve mentioned, diabetes signs and symptoms can also occur with other diseases, so testing will play an essential role in helping to determine the diagnosis. With diabetes, high sugar levels are found in the bloodstream and urine. 

With a chemistry panel, aside from high levels of glucose, high levels of cholesterol and increased liver enzymes may also be seen. 

Some elderly cats can develop high blood sugar that’s stress induced. These same levels can be observed in felines with a diabetes diagnosis. Because of this, it’s important to come to a diagnosis only after testing the urine to determine whether or not glucose is present. 

Gastrointestinal Disease 

Gastrointestinal Disease in Cats

Many types of GI diseases can lead to weight loss. GI lymphoma is the most common type found in cats over the age of ten. This is an incurable form of cancer. A cat with this disease usually has a poor appetite and is often lethargic. 

Inflammatory bowel disease has also been linked to this type of cancer. IBD involves a variety of gastrointestinal disorders that lead to an increase in the number of inflammatory cells found in the lining of the stomach. Food allergies and sensitivities can play a role and may even contribute to poor immune function. 

Chronic vomiting and diarrhea are common symptoms that result in scar tissue and inflammation of the stomach lining. 

Chronic Kidney Disease 

Fifty percent of cats over the age of ten suffer from CKD, which means the kidneys have deteriorated over a period of years. Some symptoms of kidney failure include urine leaking, an increase in urination and thirst, diarrhea, vomiting, depression, weight loss, lack of appetite, and an increase in fatigue. 

How to Fatten up Cat 

If your elderly cat normally eats processed cat food, many vets recommend making the slow transition to a fresh, balanced, non-GMO, organic diet. Whether your cat’s diet is processed or fresh, the goal should always be to ensure they’re eating something. 

Unlike with dogs, it can be very dangerous for a cat to go any length of time without food, especially when they’re seniors. Keeping an elderly cat well-nourished may require some creativity and some gentle encouragement, not to mention a lot of patience. 

Here is how to fatten up cat safely:

  • Offer a strong smelling canned cat food that’s topped with salmon or sardines
  • In case your cat has developed an aversion to their food dish, offer food on a plate
  • Offer them a small amount of a few different types of canned cat foods with different textures 
  • Warm the food to bring out the aroma
  • Entice your cat with human food that’s species appropriate such as salmon or chicken. You should be aware of the health risks of feeding a cat raw chicken, of course.
  • If your cat refuses everything but dry food, try adding water or goat’s milk to the dry cat food. 

Of course, when you’re trying to entice your cat to eat and help them gain weight, you also have to be careful not to overfeed your cat or give them something that will upset their stomach, especially if they commonly deal with diarrhea or vomiting. This can be very tricky. 

If your cat has a sensitive stomach, we recommend avoiding greasy protein sources such as salmon. Additionally, you’ll need to be careful of the protein content as an older cat’s body has a harder time digesting protein.

For sensitive cats, try mixing two tablespoons of boiled or baked chicken breast with a ¾ cup of white rice. 

Try offering this in between meals. You may find that your cat will prefer this over their normal kibble. 

Cat Losing Muscle Mass in Hind Legs 

A cat losing muscle mass in hind legs is suffering from muscle atrophy, which occurs when the muscles are no longer used due to arthritis, surgery, or injury. But this condition is actually reversible.

There are some things you can do to help your pet build up those atrophied muscles. However, it will take some dedication and persistence on your part. 

Rebuilding Atrophied Muscles 

Begin by having your pet lie on a comfortable blanket and massage the tight muscles in their hind legs. Massage therapy for pets can work wonders for pets who are not able to support their weight. 

Next, place one hand on each side of their leg joint and slowly move the joint back and forth using a natural motion. This technique can loosen joints that have been immobile in cats with arthritis or an injury. In cases such as these, the muscles will need to learn how to flex to grow. 

Use a stability ball on a non-skid rug. Pick up your cat and allow them to smell and examine the ball. Put their front paws on the ball while you stand directly behind them. Place one hand on each side of their stomach to help them balance on the ball using their hind legs. 

Next, move the stability ball gently, side to side as you support your cat. This simple movement can work to rebuild muscles in the hind legs without causing strain or injury. To strengthen the muscles try moving the ball forward and backward.

Building these muscles will help improve your cat’s balance. Try practicing this move for ten minutes a day and make sure you give your cat a treat for their participation. This will encourage them to remain patient during the exercises. 

Focus on gradually increasing the time spent on the stability ball to build up the muscles slowly. If your pet becomes stressed or anxious, then stop treatment for the day. If your cat’s muscles become sore, they may refuse to participate again. 

When Extra Care is Needed

If your cat is suffering from weak hind legs, try helping your cat groom himself in areas he’s not able to reach due to injury or weakness. Since cats love to be clean, he or she will appreciate this. 

If your cat is experiencing changes in mobility due to weak hind legs, make sure he or she has easy access to the litter box, water, and food. This can prevent muscle strain. 

What Causes Hind Leg Weakness and Muscle Atrophy? 

If your feline’s hind legs are weak, they’re not able to jump, and they walk on their hocks or with a stiff gait, then there is something wrong. Your cat may be suffering from age-related arthritis, a slipped disc, or even a tumor. 

Joint Health 

Old cats commonly struggle with joint health. Cats that have arthritis, joint cartilage that’s deteriorating, and joint inflammation are often diagnosed with osteoarthritis. Lameness is a common sign, accompanied by a difficulty walking and completing normal tasks such as accessing the litter box or grooming. 

Osteoarthritis can be an effect of abnormal wear on the cartilage and joints or trauma. If your cat is overweight, this can also put undue stress on their joints. Unfortunately, there is no cure, but the condition can be managed. 


Parasitic, fungal, bacterial, and viral infections can affect the spine, resulting in rear leg weakness. A condition called feline infectious peritonitis causes inflammation of the spine. Partial paralysis and spinal pain are common symptoms of FIP. 

Feline leukemia can cause nerve damage that can result in rear leg weakness and the loss of motor control. 

Fungal diseases can also affect the central nervous system, leading to total or partial paralysis and spinal pain. 

Cardiovascular Conditions 

A heart condition can impact a cat’s ability to use their back legs. Hypertrophic cardiomyopathy involves a thickened or enlarged left ventricle that affects the ventricle’s ability to deliver blood to the aortic valve. Cats with this condition will experience sudden rear leg weakness, loss of appetite, an increase in fatigue, and a weak pulse. 

Older Cat Not Gaining Weight 

Older Cat Not Gaining Weight

Unexplained weight loss in cats can be worrisome. Typically, cats that lose weight are often sick. A healthy cat, even an old one, will weigh the same year after year.

Unlike with weight gain, which occurs because a cat simply overeats, several diseases and illnesses can cause a cat to lose weight. If you’ve noticed your older cat not gaining weight, even if your cat is getting skinny but still eating, your first step is seeking medical attention. 

Unfortunately, it can be tough to notice exactly when the weight loss begins. This often seems to happen rapidly. One day your cat appears healthy, and the next, your older cat is skin and bones. In most cases, this weight loss is in fact gradual. But spotting when your cat loses one or two pounds isn’t easy, and weight loss isn’t always obvious. 

If your cat continues to eat normally, but they aren’t gaining or maintaining weight, an underlying health condition is often to blame. 

There is a myth associated with weight loss and an aging cat in which most people believe this is normal when it’s actually not. 

Gaining weight can indicate that a cat’s healthy aside from the fact that they’re lugging around too much weight. But it shows that their body can make use of the calories. 

A cat that’s not able to gain weight is a different ball game. 

So, what can cause this type of weight loss in an older cat? Many of the same conditions we have already covered here, such as hyperthyroidism, GI related diseases, and hyperthyroidism can all be to blame.

Minor Causes of Weight Loss 

Of course, we all hope the reason our aging pets are losing weight is a simple fix, and it might be. 

Is the cat’s food accessible? Even if you’re fairly certain that food inaccessibility isn’t an issue, it’s something you should consider.

 Here are some reasons your cat may not be able to access their food:

  1. Your cat may be bullied by another cat in the home
  2. Your cat may find it difficult to jump over baby gates or up onto a cabinet to reach their food
  3. The food is located too close to a litter box.
  4. Your cat may have internal parasites.

If your cat is suffering from a significant infestation, the cat is basically handing over most of their nutrition to the parasites. Even an indoor cat can get parasites, although it’s not as common as it is with outdoor pets. To check if your cat has parasites, look at their abdomen.

A swollen abdomen can indicate worms. Additionally, you should also check their feces and take note if it looks like their feces is speckled with sesame seeds. 

Since you won’t be able to identify exactly what’s causing your cat to lose weight, it’s important to have your cat seen by their vet. Tests such as blood panels and a urinalysis will be needed to pinpoint the cause. 

This is another reason weight loss in cats is a big problem. Not only is weight loss not very obvious until they’ve lost too much weight, but it can be difficult and expensive to determine the underlying cause.

You can’t diagnose your cat with diabetes just because they’ve lost weight or contribute it to dental issues. There are so many causes that only a medical exam and a thorough medical history can help to narrow down the possibilities. Even then, a blood panel is usually necessary.

Monitor Food Intake 

First, monitor precisely how much your cat is eating. Are they cleaning the bowl each night the way they used to? Are they only eating half a bowl? Do you still need to feed them daily or does their food tend to last two or three days?

Learning how much they’re eating on a daily basis can help you figure out if your cat is actually eating the amount they used to, or even if they have an increased appetite compared to their old eating habits. 

If your cat is still eating and losing weight, make an appointment with their vet. While ideally, they may be dealing with something as simple as parasites, if you have an indoor-only cat, then it could be something as serious as hyperthyroidism or even a tumor.

If you have more than one cat in the home or even dogs, it can be difficult to determine how much, if at all, your cat is eating. If this is the case in your home, then it’s time to separate your elderly cat’s eating area from the other animals in the home.

The weight loss may even be due to your cat not wanting to eat around other animals, another cat or dog is eating their food, or your cat feels insecure about eating around the other animals and is afraid to defend their food. 

Allowing your cat to eat in a separate room, away from the chaos of the household can help if any of the above reasons are the cause of your pet’s weight loss. 

It will also help you accurately keep track of how much and how often your cat is eating. 

Caring for Your Cat During the Golden Years 

If your old cat is otherwise healthy, it’s important that you follow the tips below to ensure he or she remains happy and comfortable in their old age.

  • First, schedule routine checkups. You can develop a close relationship with your cat’s vet and discuss your cat’s eating habits and normal routine. This should be done before your cat becomes ill. This way, your vet will become familiar with your pet and can help you pinpoint the cause of a sudden drop in weight or a change in behavior. As cats age, they need to visit the vet more often than when they were younger. Most vets recommend a wellness checkup every six months. 
  • Before you need to take your cat to the vet, minimize the stress by getting them comfortable and familiar with their carrier. The carrier should have familiar, soft bedding. This can make it easier to get your cat in their carrier when it’s time for a vet visit. 
  • Before a vet visit, compile a list of questions to ask the vet, regarding changes in behavior, bathroom habits, and appetite. This way, you won’t forget to address any issues. 
  • Pay attention to any changes in your cat’s habits. A cat can be a master at hiding an illness, and some signs can be easily missed because they’re so subtle. 

If you’d like to learn more about behaviors in elderly cats and when to call a vet, you can read our article: why is my elderly cat yowling at night? 

  • Weigh your cat. It may not be possible to get your cat to sit on a scale and patiently wait for the numbers to pop up, but you can weigh yourself alone, then step on the scale and hold your cat. Do this once or twice a month. This will help you quickly identify when there is a problem. Make an appointment with your vet if your cat has lost a pound or more.

If you’re dealing with your cat getting skinny but still eating, this is a sign that something is wrong.

As we’ve discussed, there is a wide range of diseases and conditions that can cause weight loss in elderly cats. It will be up to you to monitor their weight, make adjustments to their diet, and take them in to see their vet when you feel there is an underlying cause contributing to their change in weight, mobility, and behavior.