What to do if Your Cat is Too Thin

Waiting for momCredit: Ken SchauerSudden weight loss in cats can be alarming.  It is important to understand all the underlying causes for sudden weight loss in felines.

One way to combat this weight loss is first determine if your cat is ill.  If no sign of illness are present, then try to increase the cat's caloric intake.  

Adult cats need about forty calories per pound every day, so weigh your cat when you first change their diet, and weigh them at least once a week to determine if the change in diet is working.


Calories needed for an adult cat.  All measurements for food are in ounces.


Daily Feeding Chart

Weight in pounds Calories Needed Dry Food Semi-Moist Food Moist or Canned food
4 160 1 1/2 1 1/2 5
6 240 2 1/2 2 1/2 8
8 320 3 1/3 3 1/3 10
10 400 4 4 13
12 480 5 5 16
14 560 6 6 18

It is recommended that you gradually increase your cats weight.  If you try to go from 4 lbs to 14 lbs, you should step your up in two pound increments.

If your cat does not gain weight after increasing their diet, then you need to take your pet to the vet.  There are lot of reasons why your cat may be losing weight, or is too thin, so it would be best if a trained professional looks at your pet.

Here are a few items that can cause rapid weight loss

  • Recent change in environment (moving, new baby, new pet)
  • Hyperthyroidism
  • Diabetes
  • Kidney Disease
  • Heart Disease
  • Worms
  • Low Calorie Intake
  • Infection

The list is longer then this, so if illness is apparent with your cat, please take them to the veterinarian!  They will perform a battery of tests to determine what is wrong with your kitty.  They will assess a complete history of the feline, and perform a physical examination.  Your cat's dietary and bowel patterns will be analyzed.  The list of tests that the veternarian may perform include...

  • Blood tests (including FLV and FTLV)
  • Stool Sample
  • Urinalysis
  • Electrocariogram
  • Echocardiogram
  • Endoscopy
  • Biopsies
  • X-Rays

Please note, there is an increased chance of hyperthyroidism in cats over the age of seven.  Identifying this early can lead to better treatment for your beloved pet.

On a more personal note, my cat George went through rapid weight loss a few years back.  He became lethargic and seemed to stop eating.  A quick trip to the vet determined that he had a severe infection we could not see, and he needed home IV's for liquids and antibiotics.  While this was not a fun time for me and my wife, we managed to bring George around, and he is a healthy cat once again.  

Another one of my kitties had lost weight.  Callie was an aging calico, and it turned out that she had hypothyroidism.  She did not survive, and the vet informed me that we had discovered the problem too late.  Please take your cat to a veternarian if you have ANY doubts or concerns.