Old cat losing weight: Causes and solutions

As cats age, they tend to gain weight due to decreased activity levels and slower metabolism. However, some cats go the exactly opposite way and start losing weight. Sometimes, old cats lose weight even when they are eating normally. So what’s going on? And should you be worried? 

While some weight loss in older cats is normal, excessive weight loss can be a sign of an underlying health problem. Sadly, as cats age, they also become more susceptible to various health issues, which can result in weight loss. 

If your old cat is losing weight, it is important to take her to the vet for a check-up. Your vet can help determine the underlying cause of the weight loss and recommend an appropriate treatment plan. 

In some cases, simply changing your cat’s diet or providing more frequent, smaller meals may help. In other cases, medication or even surgery may be necessary. 

And sometimes, especially with very old cats, you need to get very creative to get them to eat ☺️

I hope this guide will help you get your senior cat back in shape. So let’s dive in!

This post may contain affiliate links, which means I may receive a commission, at no extra cost to you, if you make a purchase through a link. Please see my full disclosure for further information.

While I am a veterinarian, this article is not intended to replace professional veterinary advice. If you have any medical concerns about your pet, consult your vet immediately. Always seek professional assistance if you are unsure of your pet’s health.

thin old ginger cat

Most common causes of old cat losing weight

There are several reasons why very old cats get skinny and you can actually feel their bones when you pet them. 

As cats age, they become more susceptible to various health conditions which can directly result in weight loss. On top of that, their metabolism changes, and their ability to absorb nutrients from their food starts to decline. 

So losing weight is a common problem in cats, especially in very old (geriatric) cats. Since unexplained weight loss can be a sign of an underlying health issue, it is important to address it promptly. 

Basically, weight loss in senior cats can be attributed to insufficient diet or to an underlying health issue. 

Rapid or sudden weight loss can indicate a serious problem and requires immediate veterinary attention.

Weight loss in cats can be caused by a variety of factors, including:

  • Dental problems
  • Hyperthyroidism
  • Chronic kidney disease
  • Cancer
  • Diabetes mellitus
  • Gastrointestinal disorders
  • Arthritis
  • Parasites
  • Stress
  • Insufficient nutrition


Hyperthyroidism is a condition that occurs when the thyroid gland produces too much thyroid hormone. This can cause weight loss, as well as other symptoms such as increased appetite, thirst, and urination.

Diabetes mellitus:

Diabetes mellitus is a condition that occurs when the body is unable to properly regulate blood sugar levels. This can cause weight loss, as well as other symptoms such as increased thirst, urination, and appetite. 

Dental issues:

Dental problems are also a common cause of weight loss in older cats. Tooth decay, gum disease, and other dental issues can make it difficult for cats to eat. If you have a cat, you need to know how to properly care for her teeth.

However, in some cases, cats can lose all their teeth. These toothless kitties might need extra care to help them lead a happy and full life.

Intestinal parasites:

Did you know that indoor cats can also get parasites? Yep, you need to regularly deworm your cat, regardless if she goes outside or not. And while healthy mature cats can usually deal with a parasite infection (unless it’s massive) without any serious health issues, senior cats can experience more serious signs. 


Did you know that 90% of cats over 12 years old show signs of arthritis? While feline arthritis doesn’t cause weight loss directly as some other diseases, it can contribute to slow loss of weight and muscle mass. Arthritis is a painful condition, and pain in cats often leads to decreased appetite. It can also make walking and retrieving food painful. 

Chronic kidney disease:

Chronic kidney disease is a common health problem in senior animals. Sadly, it often goes unnoticed, since kidneys have a huge ability to compensate for the loss of function. Often we see clinical signs only when there is already a significant decrease in renal function.

The usual symptoms of kidney disease are lack of appetite, weight loss, increased thirst, Increased frequency and amount of urination, and diarrhea or vomiting. 

Insuffcient nutrition:

Sometimes old cats start losing weight due to changes in their metabolism. They are no longer able to absorb all the nutrients they need from their diet and start losing muscle mass and body weight. This is the main reason why senior cats need a nutrition-rich diet to keep their resting body weight. 


Cancer is another common health condition in older cats that can lead to rapid weight loss. Since there are many different types of cancer, I am not going into more detail in this post. Let’s just say that the older the animal is, the higher the risk of developing cancer. 

Gastrointestinal disorders:

Infections, chronic gastrointestinal problems, irritable bowel syndrome, and other diseases affecting the gastrointestinal tract can all result in weight loss. However, there are usually other signs as well, like vomiting, diarrhea, or fever. 


Stress can also contribute to weight loss in cats. Older cats may experience stress due to changes in their environment, such as the addition of a new pet or family member, or changes in their routine. To help manage stress, provide your cat with a quiet and comfortable space to retreat to, and try to maintain a consistent routine.

As you can see, weight loss is such a general symptom, that it can be caused by a number of underlying health issues. So if your older cat is losing weight, it is important to take her to a veterinarian for a thorough examination. 

Your veterinarian can help determine the underlying cause of the weight loss and develop a treatment plan to help the cat regain weight and improve her overall health.

Most common causes of weight loss in senior cats - inforgraphic

Other symptoms and signs to look for

As cats age, their bodies undergo various changes that can impact their overall health and well-being. And while some weight loss is normal in very old cats, unexplained weight loss accompanied by other symptoms is usually a sign of underlying health issues. 

Here are some symptoms and signs to look for if your older cat is losing weight:

  • Decreased appetite: A decrease in appetite can be a sign that your cat is not feeling well or that she’s having a dental problem. If your cat is not eating as much as usual or is refusing to eat altogether, it’s important to take her to the vet for an evaluation.
  • Increased drinking: If your cat is drinking more water than usual, it could be a sign of kidney disease or diabetes. Your vet can perform tests to determine the cause of the increased thirst.
  • Bad breath and dental problems: Dental issues often cause cats to lose weight. If your cat has bad breath, red inflamed gums, or has difficulty eating, it’s important to take them to the vet for a dental exam.
  • Vomiting and diarrhea: These symptoms can be caused by a variety of health issues. Again, take your cat to a vet.
  • Constipation: If your cat is straining to defecate or is producing small, hard stools, it’s important to seek veterinary care.
  • Mobility issues: If your cat avoids going up and down the stairs, doesn’t want to move very much, and doesn’t want to play, she might be suffering from arthritis. However, cats are notoriously good at masking their pain and often show no signs of painful joints.
  • Urinating outside of litter box: In cats urinating outside of their litterbox is always a sign that something is going on. 

If your cat is experiencing any of these signs, it’s important to take her to your vet for an evaluation. 

Diagnostic procedures and treatments

As I said before, when an old cat is losing weight, it is important to take her to a vet for a physical exam. Your veterinarian will examine your cat for any signs of illness or injury. He may also order further diagnostic tests to help determine the underlying cause of the weight loss.

Common diagnostic tests are x-rays or ultrasound examination, which can help identify any abnormalities in your cat’s internal organs or bones. Blood tests are used to check for any abnormalities in the cat’s bloodwork, including glucose levels or kidney function. 

These tests can help identify any underlying health conditions that may be causing the weight loss.

In some cases, surgery may be necessary to diagnose or treat the underlying condition. For example, if a cat has a tumor, surgery may be necessary to remove it. 

Treatment for weight loss in old cats will depend on the underlying cause of the weight loss. 

If the weight loss is due to a benign condition, such as dental disease or an infection, treatment may involve antibiotics or other medications. 

If the weight loss is due to a more serious condition, such as cancer or kidney disease, more aggressive treatment may be necessary.

Overall, when you notice that your cat is losing weight, it’s important to take her to your vet as soon as possible. Early diagnosis and treatment can help improve your cat’s quality of life and increase her chances of recovery.

cat planner

Nutritional requirements of senior cats

As our feline companions age, their nutritional needs evolve, requiring careful consideration to ensure they enjoy a happy and healthy life in their golden years. 

Senior cats undergo various physical and metabolic changes that necessitate adjustments in their diet. Their ability to ingest all necessary nutrients declines with age. 

Proper diet and nutrition are essential for maintaining a healthy weight, preventing illness, and improving overall well-being. Choose a nutrient-rich, high-quality and highly digestible diet with all necessary supplements that supports the needs of senior cats.

So when you want to choose the best diet for your older cat, this is what you should consider:

Proteins are the key

Protein remains a vital component of a senior cat’s diet. In fact, it becomes even more crucial as they age. High-quality, easily digestible protein sources help maintain muscle mass and support overall health. 

Look for cat foods that list a high-quality protein source as the primary ingredient. Protein content should make up a significant portion of their diet to ensure they receive the necessary amino acids.

Taurine is an essential amino acid that is important for maintaining heart health and vision. Cats cannot produce taurine on their own, so it’s important to feed them a diet that is rich in this nutrient. Most commercial cat foods are fortified with taurine. But it’s something you need to keep in mind if you want to feed your cat homecooked diet.

Reduced caloric intake

One of the most notable changes in senior cats is a decrease in activity levels and metabolism. As a result, they require fewer calories than their younger counterparts. 

Overfeeding can lead to obesity, which can exacerbate age-related health issues such as arthritis and diabetes. Therefore, it’s essential to adjust their calorie intake to match their reduced energy expenditure. 

However, if your cat is losing weight, as sometimes happens with very old cats, she might need a bit more calories in her diet. In this case, I would strongly advise you to consult your veterinarian to determine the appropriate daily caloric intake for your senior cat.

Controlled fat intake

Most senior cats require less fat in their diet compared to their younger counterparts. A lower fat content helps prevent obesity and reduces the strain on aging organs, particularly the liver and pancreas. 

But again, if your cat is loosing weight instead of gaining weight, she might need a special diet to help her keep a healthy body mass.

In any case, fats should come from healthy sources like fish oil or chicken fat to provide essential fatty acids for skin and coat health.

Joint health support

Senior cats are prone to feline arthritis and joint pain. To alleviate discomfort and maintain mobility, consider feeding them foods enriched with glucosamine and chondroitin sulfate. These compounds can help protect and repair cartilage in their joints. Additionally, omega-3 fatty acids found in fish oil can reduce inflammation and improve joint function.

Health conditions

Older cats may also have health conditions that require a specific diet. For example, cats with kidney disease may require a diet that is low in protein and phosphorus, while cats with diabetes may require a diet that is low in carbohydrates. Talk to your vet about your cat’s specific needs!

Proper diet and nutrition are essential for maintaining a healthy weight, preventing illness, and improving overall well-being in older cats. Feeding a high-quality food that is specifically formulated for senior cats can help ensure that your kitty is getting all the nutrients she needs to thrive.

a ginger cat with a bowl of food

Tips and tricks on how to get a senior cat to eat

As cats age, they may become pickier eaters or experience a decrease in appetite, which can lead to weight loss and other health issues. 

If you’re struggling to get your senior cat to eat, here are some tips to try:

Choose a highly palatable diet:

Some super-premium brand make special diets for very picky eaters (for example Royal Canin Exigent). They have enhanced aroma and flavours, but still cover your senior cat’s nutritional needs. 

Very old cats can have a weaker sense of smell, and may appreciate these type of foods.

Offer a variety of foods: 

Just like humans, older cats can get bored with the same food every day, especially when it wasn’t very tasty to begin with. Try offering different types of wet and dry food, as well as treats and meat suitable for human consumption. Experiment with different textures and flavors to see what your cat prefers. 

Warm up the food: 

Heating up your cat’s food can make it more appealing and enhance its aroma. Just be sure to test the temperature before serving it to your cat! 😊

Feed smaller, more frequent meals: 

Some older cats prefer smaller portions of fresh food, instead of food that has been lying in their bowl all day long. Try feeding them more frequently or use an automatic feeder. More frequent meals are also easier on their digestive system.

Add moisture to the food: 

Adding water or broth to your cat’s food can increase its moisture content and make it easier to eat. This is especially important for senior cats who primarily eat dry food, as they may not drink enough water on their own.

Make mealtime enjoyable: 

Create a positive association with mealtime by feeding your cat in a quiet, comfortable location away from distractions. This is especially important if you have several cats or a baby that keeps distracting your cat. 

You can also try using puzzle feeders or hiding food around the house to encourage your cat to eat.

Consult with a veterinarian: 

If your cat still isn’t eating, it’s important to consult with a veterinarian to rule out any underlying health issues. Your vet may also be able to recommend a prescription diet or appetite stimulant to help get your cat back on track.

By following these tips, you can help ensure that your senior cat is getting the nutrition she needs to stay healthy and happy ☺️

How to get your senior cat to eat - infographic

Frequently Asked Questions

How can I tell if my senior cat is losing weight?

You can tell if your senior cat is losing weight by regularly weighing them, observing their body condition score, and checking for any physical changes. Here’s a nice guide on how to use cat body condition score (don’t worry, it’s easy!☺️)

A healthy cat should have a rounded abdomen, and you should be able to feel her ribs without pressing too hard. If you notice any visible bones or a sunken appearance, it’s a sign that your senior cat is losing weight.

What are some signs of malnutrition in senior cats?

Signs of malnutrition in senior cats often include lethargy, weakness, loss of appetite, dehydration, constipation, and poor coat quality. If your senior cat is showing any of these symptoms, it’s essential to take her to your vet for a check-up!

How can I help my older cat gain weight?

You can help your older cat gain weight by feeding her small, frequent meals throughout the day, providing her with a high-calorie diet, and making sure they have access to clean water. If you want to give your cat a high-calorie diet, talk to your vet first! You can also ask him about supplements or vitamins that can help your cat get back to her optimal weight.

Recommended foods for senior cats include high-quality, protein-rich food that is easy to digest. You can also feed her a balanced, age-appropriate diet that includes essential nutrients like vitamins, minerals, and fatty acids.

What can I do if my senior cat is losing weight despite eating normally?

If your senior cat is losing weight despite eating normally, it’s essential to take her to the vet for a check-up. Your vet may recommend a specialized diet, supplements, or medication to help your senior cat gain weight. It’s crucial to follow your vet’s advice and monitor your cat’s weight regularly!

Weight lost in older cats is a concern that strikes a chord with countless pet owners who share their lives with senior feline companions. As our beloved cats age, we expect certain changes in their health and behavior, but unexplained weight loss can be a perplexing issue. Many pet owners wonder if it’s normal or if they should be worried.

Sadly, weight loss can be a subtle but significant indicator of an underlying health problem. Therefore it’s crucial to consult with a veterinarian if you notice any changes in your cat’s body condition. 

I hope this guide helped you understand the significance of this subtle sign and the importance of senior cat nutrition 🥰

So now that you know all about weight loss in older cats, here’s what to read next:

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