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Why is my senior cat losing weight, always hungry, and has diarrhea?

Updated on September 23rd, 2025

Pet's info: Cat | Mixed Breed | Male | neutered | 6 lbs

Really need some advice. My 10'yr old has dihorea and no matter what he eats he cries for more, begging for food. He's lost 1/4 of his body weight. Our vet doesn't seem to bothered but it's hard seeing my boy like this. Vet said he had renal failer and he's on a renal diet but it's made him even more hungry and not helping. I've attached the results from blood test, I just don't get it. I thought cats with renal failure lost their appitite and not increased. And info would really help. Thanks

2 Answers

Most Helpful Answer

Answered By Lindsey Edwards MVB, BSc, IVCA

Veterinarian

Published on June 14th, 2018

These are indeed an unusual set of symptoms, thyroid disease and diabetes would be the first suspects for a cat with increasing appetite and weight loss. A specialist ultrasound scan of the abdomen may be worth while to investigate difficulties with food digestion and absorption or even tumours using up the calories

1Pet Parents found this answer helpful

Related Answers from Veterinarians

Answered By Amber Da Silva, DVM
Veterinarian
Published on January 11th, 2018
I'm sorry to hear the Mr. Kitty is not acting himself lately. Based on your description of his symptoms, I would either suspect diabetes or hyperthyroidism. Both of these diseases commonly cause rapid weight loss even with an increased appetite. Obese cats are especially at risk for diabetes. Both of these diseases are diagnosed by blood tests. I would recommend that you take him to a veterinarian as soon as you can in order to diagnose him and start treatment. Both of these diseases can result in many secondary problems, so the sooner he is treated, the better the outcome can be. While having worms can cause weight loss and diarrhea, this is uncommon in adult cats. It is usually seen in very young cats with a very large number of worms. I hope this helps and that Mr. Kitty gets feeling better soon. Thank you for using Petco Pet Education Center, formerly Petcoach!
1Pet Parents found this answer helpful

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