Why Did My Kitten Lose Weight? A blog explaining why your kitten has lost weight and how you can help with it.


Kittens are cute, but they can also be difficult to care for. Like babies, kittens need to eat more than adults and have higher nutritional needs in general than adult cats do. If your kitten is losing weight (or not gaining weight as quickly as it should), here are some common causes and how they can be addressed:

Metabolic diseases

Although it’s not exactly a disease, obesity can be caused by an underlying metabolic disorder. A cat with this ailment will have a very hard time losing weight even when they’re fed the best diet, and may require medication to control their appetite and prevent further weight gain as well as insulin injections to treat diabetes.

A healthy kitten should lose between 1% and 2% of their body weight per month when they’re growing (1-2 pounds for every 10 pounds of body weight). If your kitten is eating plenty of food but still losing more than that amount, it could be because they’re not getting enough exercise. Cats need at least 30 minutes of playtime each day in order to maintain a healthy metabolism–both physical activity and mental stimulation are important factors! The best way you can help your kitten lose weight is by encouraging them to play outside or with toys instead of being inactive all day long–you’ll both benefit from the extra exercise that comes with it!

Dental problems

A dental problem can be the culprit behind your kitten’s weight loss. In fact, tooth abscesses are one of the most common causes of this symptom in cats and kittens.

Your kitten may have an infection in his teeth that results in pain when he eats. The abscess is usually somewhere near a tooth root or crown (the part of the tooth visible above the gum line), but it can also be below it if there’s been trauma to that area.

If you suspect your kitten has a dental problem, take him to see a veterinarian as soon as possible for treatment and diagnosis. If left untreated, this issue can spread throughout your pet’s body—causing more severe health problems than just weight loss alone!

GI parasites

If your cat has lost a lot of weight, it could be the result of an intestinal parasite. These can include roundworms and tapeworms, as well as hookworms. They all present with similar symptoms: diarrhea and vomiting (often bloody), but also lethargy, fever, loss of appetite and dehydration.

If you suspect your kitten has been infected by one of these parasites, your veterinarian will test her stool for parasites using a fecal sample. If the results are positive for any kind of parasite (and it’s not uncommon for kittens to have multiple different kinds), they will prescribe medication that treats the infection and kills off any remaining parasites in her system.


Diabetes is a disease in which the body does not produce or properly use insulin. Insulin helps to regulate blood sugar levels and keep them within a healthy range. When your cat has diabetes, either their pancreas isn’t secreting enough of this important hormone or their cells are unable to respond to it properly. This can cause your kitty to lose weight and urinate more frequently than usual. Your vet may recommend keeping an eye on your cat’s blood glucose levels by checking their urine once per week or so until they are diagnosed with diabetes or rule out any other conditions that could be causing them to lose weight.

Diabetes can be treated with insulin injections twice per day, however some cats respond better if they take oral medications instead of getting shots every day for life (which is pretty much forever).


  • Cancer is a common cause of weight loss in cats. Cancer can affect any organ in the body, including the mouth and stomach. It’s important to get your kitten checked out by a vet if you notice any changes in their eating habits or other signs of illness.
  • A physical examination and blood tests are usually enough to detect cancer in cats. If your vet suspects that your kitten has cancer, she may recommend further testing such as x-rays or ultrasounds. These may be painful for your cat but will help her receive treatment sooner rather than later.
  • Treatment options depend on what type of cancer it is and how far along it has progressed, but they can range from surgery to chemotherapy or radiation therapy—all options that require expert knowledge from a veterinarian who specializes in feline care!


Weight loss is one of the most common symptoms of hyperthyroidism, which is also known as an overactive thyroid gland. This condition affects about 6 percent of cats in the United States and can be treated with medication.

In rare cases, a brain tumor can cause an increase in hormones that lead to weight loss. If your veterinarian thinks this may be the cause, they will perform tests on your kitten’s blood and radiograph his bones to help determine if he has cancerous cells growing inside him that are causing his symptoms. It’s important that you get answers as quickly as possible because once diagnosed with cancer, cats usually don’t live very long—usually less than six months after diagnosis!

Kittens can lose weight for a variety of reasons. With treatment, your cat should be back to its normal self soon.

There are a number of reasons that your kitten may be losing weight. They include:

  • Ingesting foreign objects
  • Dietary changes
  • Bacterial infection, such as urinary tract issues or parasites like roundworms and tapeworms
  • A medical condition, such as hyperthyroidism or diabetes

Regardless of the cause, you should always bring your pet’s symptoms to the attention of a veterinarian so they can be properly evaluated and treated. If your cat is having problems gaining weight after these conditions have been ruled out, it could indicate something more serious like cancer or kidney disease.


The best thing you can do is take your kitten to the vet, so they can run some tests and make sure they are healthy. They will also be able to give you advice on how to help your cat recover from whatever condition it has been diagnosed with. Hopefully this article has helped you understand what might cause a kitten’s weight loss and if there are any other signs of illness in your pet.

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