If you have an older cat that is losing weight, you’re probably worried about them. While weight loss is a normal sign of aging, it could indicate a health problem.
So, what health problems can cause weight loss in cats? How can you help your feline during this tough period?
Read on to learn about eight possible reasons that your feline is losing weight, how to recognize the signs of these issues, and how to help your feline maintain a normal weight.
The 8 Vet-Approved Reasons Why Older Cats Lose Weight
1. Chronic Renal Disease (Chronic Kidney Disease)
Chronic renal disease, also known as chronic kidney disease (CKD), is a common condition in older cats; it represents a persistent kidney function loss, which can cause multiple health issues for your feline. Cats that suffer from CKD experience a buildup of various harmful compounds in their bloodstream, which leads to several problems, including:
How to Help Your Feline
Unfortunately, there’s no way to entirely cure CKD, so felines suffering from this problem can never become fully healthy. However, with proper treatment, your cat could live a somewhat normal and long life.
The treatment for CKD typically includes dietary changes and medication to minimize the toxins inside your cat’s blood.
2. Diabetes Mellitus
Another common reason for older cats to lose weight is diabetes mellitus. This condition can affect cats of all ages, but it’s especially noticeable in older cats. There are three different types of diabetes mellitus:
- Type I — This type is quite rare in cats.
- Type II — This is the most common type of diabetes in cats, and it’s typically triggered by obesity.
- Type III — This type is somewhat common in cats; it usually occurs due to hormonal changes happening in your feline’s body.
When a feline has diabetes mellitus, their body is incapable of regulating glucose levels, which may lead to several clinical signs, including:

How to Help Your Feline
Fortunately, diabetes mellitus is a treatable condition in cats, though it will require your determination and persistence. The initial step in helping a cat with diabetes mellitus is to find out the cause of the problem.
In most cases, your vet will recommend a diet change and insulin injections, and you’ll need to monitor your feline’s progress and consult your vet if any changes occur.
3. Hyperthyroidism
If you’ve recently noticed that your older cat is losing weight but they have a normal or even increased appetite, your feline may be suffering from hyperthyroidism. This is a common condition in cats that are over 8 years old; it occurs when your feline’s thyroid gland produces more thyroid hormone than it’s supposed to.
Common signs of hyperthyroidism in cats include:
This condition develops gradually, so it can be challenging to notice all the signs. However, you should observe your feline and take them to the vet if you notice any of them. Leaving hyperthyroidism untreated for a long time could lead to other health problems, such as heart disease and hypertension, which is why it’s crucial to react promptly and help your feline.
How to Help Your Feline
Your veterinarian will prescribe treatment for your cat to treat their hyperthyroidism, typically oral medications that contain methimazole. However, these drugs can cause side effects that may lead to other health problems, so remember to be cautious during this period and strictly follow your vet’s advice.
4. Inflammatory Bowel Disease
If your older feline is losing weight, they might be suffering from inflammatory bowel disease. This condition is common in old cats, and it affects your cat’s gastrointestinal tract and causes inflammation and irritation. This leads to your feline’s GI walls becoming thicker and losing the ability to properly absorb and digest food.
There’s still no evidence as to what causes inflammatory bowel disease, though most people believe that this condition occurs when there’s an abnormal situation in your feline’s:
When a feline is suffering from inflammatory bowel disease, they will likely experience the following signs:
As the signs of this health condition are similar to those of many other feline health problems, it’s best to consult your vet if you notice any of them, so your cat can undergo further testing.

How to Help Your Feline
If your feline is suffering from this disease, your veterinarian will probably prescribe medications and require you to make a change in your feline’s diet. Some felines may require corticosteroid treatments if other medications don’t work.
5. Dental Disease
Another common issue that can lead to weight loss in older felines is dental disease. Common variations include:
The problem with noticing a dental disease in your feline is that they typically don’t show any signs that you can closely track. Still, some felines suffering from dental problems will display signs like:
How to Help Your Feline
If your feline is suffering from dental disease, you’ll need to take them to a vet check-up to determine the precise variation that you’re dealing with. Fortunately, most feline dental problems are easily treatable with proper medications.
6. Cancer
It’s common for many older cats to experience weight loss due to cancer, and there are various types that your feline could have. This type of health problem is especially common in older cats.
Lymphoma is the most common type of cancer that affects cats, and it presents several clinical signs, including:
Another common cancer in cats, squamous cell carcinoma, has similar signs, including:

How to Help Your Feline
If your veterinarian confirms that your feline has cancer, they will determine what type of treatment is available for your feline. Each type of cancer is different, so the treatment will depend on what your cat has and its development stage.
7. Arthritis
A common condition that affects older cats and can eventually lead to weight loss is arthritis. This degenerative condition leads to painful joints and makes moving uncomfortable.
Common signs of arthritis in cats include:
If you suspect that your feline may have arthritis, it’s best to visit your vet for further testing and possible treatment options.
How to Help Your Feline
Unfortunately, there’s no cure for feline arthritis. However, you can help your cat and make their life slightly easier by making environmental and dietary changes. You’ll be able to ease their pain and make their life more comfortable.
8. Pancreatitis
If you notice that your older cat has suddenly lost weight, they might be suffering from pancreatitis. There are two different types of pancreatitis that your cat may experience:
Cats suffering from pancreatitis will experience the following signs:

How to Help Your Feline
The treatment for pancreatitis will depend on the severity of the condition. Treatment focuses on management of dehydration, nausea, pain and nutrition.
Most of the time, your vet will prescribe fluid and hydration support, anti-nausea and nutrition support. In cases with concurrent disease, anti-inflammatory medications, analgesics, and antibiotics. Some cats that suffer from this condition may end up hospitalized for a couple of days to receive IV fluids and medications.
Conclusion
If you notice sudden weight loss in your old feline, there’s no need to panic. Instead, remain calm, and look for other signs that indicate that your feline is experiencing a particular health problem. Sometimes, weight loss in your cat is just a normal side effect of aging, while other times, your feline may have a problem and need medical help to maintain a normal weight.
Featured Image Credit: Benchamaporn Kanlapungha, Shutterstock