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If your cat eats a lot but still loses weight, it’s time to call the vet

When it comes to being a pet parent, two of the most important tasks you’ll take on are helping your fur baby maintain a healthy weight and feeding your feline companions nutrient-rich meals. Have you been wondering, “Why is my cat losing weight?” A variety of reasons, some benign and some life-threatening, could be to blame. If you’ve noticed that your cat is overeating, or even if your cat simply continues to eat normally but still manages to lose weight, do not delay — take them to see the veterinarian right away.

Unplanned loss of weight in cats can be a symptom of a number of health complications that should be checked out immediately. You definitely don’t want to just take a “wait and see” approach or assume your cat will suddenly start to put on weight again. Remember, prompt treatment is essential for your cat’s well-being.

Cat with empty bowl looking up

How can I tell my cat is losing weight?

The best way to tell whether your cat is losing weight is simply by paying attention and performing weekly checks. It can be tough to tell if weight loss is occurring if your cat has a lot of fur, so the best thing to do is to feel the sides of your cat’s body to see if their ribs are protruding or if there are any noticeable changes to their body composition. Dr. Ken Lambrecht, a veterinarian from Madison, Wisconsin, told Catster, “You can do that in combination with petting them and giving them affection, and just kind of feeling muscle mass and general mass.”

Vet listening to a longhaired cat's heart

What you should do about your cat’s unintentional weight loss?

Lately, you’ve noticed that your cat is displaying troubling symptoms of weight loss. Your feline friend has been eating regular meals and even enjoying snacks, but still seems to be getting lighter and lighter. You’ve probably started to wonder what’s going on.

It is essential to your fur baby’s health that your cat maintain a healthy weight for their age and breed. That’s why if you’ve noticed your cat suddenly lose weight — with or without changes in appetite —  you need to contact your veterinarian as soon as possible.

cat eating

Why is my cat losing weight?

There are many medical issues that can cause your kitty to lose weight, and you should be aware of the most common causes of sudden weight loss. Let’s explore some of the most common possibilities.

Emotional issues

Some of the most common emotional causes are stress, anxiety, and depression. If you’ve recently introduced other animals to your home, moved to a new home, or noticed your cat’s behavior change in other unpredictable ways, these mental-health issues might be areas for your vet to address. If you have noticed that your cat is generally less interested in his food, this could possibly be caused by feline anorexia. All of these conditions can be successfully treated by a licensed professional.


If your cat has hyperthyroidism, they will urinate and drink a lot more because the condition sends their metabolism into overdrive. It usually occurs when a benign tumor is present on the thyroid glands. It’s a very serious condition that can also lead to heart disease, stroke, and blindness, so be sure to contact your vet immediately if you suspect it.

Gastrointestinal issues

Gastrointestinal (GI) problems can occur in cats that have inflammatory bowel disease, infections, or allergies to foods they have eaten. If you’ve noticed that your fur baby suffers from nausea, diarrhea, and vomiting, those are all strong indicators that your cat is suffering from a GI issue.

Invasive parasites

Many of these same symptoms — like diarrhea and vomiting — will also be present in cats struggling with invasive parasites. These unwanted guests could be living inside your cat and causing weight loss. Because different parasites require different treatments, we recommend taking your cat to the vet if you suspect a parasitic infestation.

Organ failure

Organ failure can be another cause of this issue that frequently occurs in older cats. As cats age, severe health conditions become more likely. Common ailments older cats suffer from include cancer, diabetes, and conditions such as feline infectious peritonitis. All of these conditions require a proper diagnosis from your veterinarian.

While many conditions that cause weight loss in cats are serious, please try not to panic. Weight loss can also be caused by much less frightening health issues, such as a toothache or other dental problems. Only your vet is qualified to be able to know for sure what’s going on with your cat, so now is the perfect time to bring Fluffy in for an exam.

Veterinarian examining cat while owner holds it

What to do if you can’t see your veterinarian right away

If you are concerned about your cat but unable to see your vet right away, try not to worry yourself too much. Instead, keep detailed records containing as much information as possible about what’s going on with your cat, and then give your vet a call. Explain what’s happening in detail, listen, and follow their advice.

In many situations, your vet will be able to make recommendations over the phone that could help your cat right away. They could recommend different feeding options. They might still recommend bringing your cat in to see them, but at least after speaking on the phone, you will be able to make a plan together that works for everyone.

We can’t stress this enough: If you are concerned about your pet, call your vet as soon as possible. By the end of the call, you will likely feel much better than before you reached out.

In conclusion

When your cat is eating normally and cannot maintain their weight, it could be due to a serious issue. Treat it like one and seek medical attention as soon as possible. Though it might be stressful, talking with your veterinarian is the first step to getting your feline companion back to their healthy, happy, and vibrant self.

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