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Why is my senior cat always hungry but losing weight? Hyperthyroidism?

Updated on September 23rd, 2025

Pet's info: Cat | Mixed Breed | Female | spayed

My 16 year old cat seems to lately be eating enough but being constantly hungry. Near her butt bone she is so thin that it looks like she's starving

5 Answers

Most Helpful Answer

Answered By Destini R. Holloway, DVM

Veterinarian

Published on July 30th, 2016

When an senior cat is eating more frequently yet losing weight, this can be a sign of hyperthyroidism. With hyperthyroidism, the thyroid gland is secreting too much hormone which causes an increase in the pets metabolism and subsequent weight loss. Have your vet check Hopes T4 levels to see if she is hyperthyroid and in need of medication to help stabilize her hormones so that she doesn't continue to waste away. This is easily diagnosed and treated with medication (i.e. Methimazole).

Your vet will also want to run baseline bloodwork on your pet to make sure no other disease processes are there.

19Pet Parents found this answer helpful

Related Answers from Veterinarians

Answered By Dr. Massimo Orioles, DVM, Cert AVP, MRCVS
Veterinarian
Weight loss despite excessive appetite is a common sign in old cats which may be compatible with metabolic disorders such as hyperthyroidism and diabetes mellitus. Other differentials are possible (liver and gastrointestinal diseases).

I would strongly recommend to have Hope checked by your veterinarian and have a blood test and urine analysis performed (including thyroid profile).
15Pet Parents found this answer helpful
Answered By Dr. Strydom, DVM
Veterinarian
Published on October 11th, 2019
The most common reason for an older cat to eat well but still lose weight is hyperthyroidism. No food you feed is going to help this. You have to get the thyroid levels under control. I suggest you take Lily to your vet for an exam and some blood testing. An elevated thyroid level can be easily found on routine blood testing and the treatment is not expensive.

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1Pet Parents found this answer helpful
Answered By Andrea M. Brodie, DVM
Veterinarian
Published on January 12th, 2019
I suggest you get a second opinion from another veterinarian. Your kitty could be suffering from hyperthyroidism (easily diagnosed with a blood test, and easily treated) or a kidney condition. I suggest you schedule an appointment with a veterinarian for an exam and blood tests. Cats do not just lose weight without a reason. If they cannot eat enough they usually have a health problem as described above or bad teeth and gingivitis.
1Pet Parents found this answer helpful
Answered By Laura Johnson VMD
Veterinarian
Published on April 8th, 2018
Hi, thanks for using Petco Pet Education Center, formerly Petcoach! Poor Baby Cakes!

The most comon causes for weight loss and increased hunger in an older cat is hyperthyroidism and diabetes. Both can increase vomiting as well. Before changing her food I’d recommend a Vet visit and blood work. If that’s all normal then we can try a food change.

I hope this helps!
1Pet Parents found this answer helpful

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