10 year old male cat losing weight. Why?

by April
(Hamilton, Ontario Canada)

My male cat of about 10 years has just recently been losing weight. What could be the problem?

We got our brother and sister cats when they were 8weeks old in 2001. They are indoor cats and have all their shots, etc.

The girl cat eats only dry kibble where as my cat Kali (male) eats moist as well.

Just recently Kali has been losing weight to the extent that when I pick him up it is very noticeable. I am worried and would like to know what could be the reason?

My sister-in-law is a vet in Australia and says he needs blood work, but it could be that he is anemic or it could be his liver?

Can someone please shed some information if you have ever had this happen to a family member (cat). Thank you so much.

April Martin (Canadian Resident)

Editor's note: I'm sorry to hear that Kali is losing weight. Hopefully someone with experience can step in here and give you their perspective, but I'll tell you what I think I know.

Any kind of noticeable weight loss in a cat requires a visit to the vet to find out why.

There are many possible causes for weight loss in cats. Some that come to mind are diabetes, parasites, and cancer. There is no way to know what's wrong without having a full veterinary exam and I'm sure they'll want to do blood work.

At 10 years old, he should probably have blood work done anyway, because he is susceptible to the diseases that occur more frequently in aging cats. We like to think of our cats as perpetual kittens, but the truth is that 10 years old is getting up there.

One of those diseases is hyperthyroidism. Overactive thyroid leads to hyperactivity and weight loss. Another is diabetes as I mentioned above. With diabetes, blood sugar gets out of balance, and the cat's body starts breaking down fat and protein and loses weight.

Another is chronic kidney disease. All of these can lead to weight loss, but they're not the only ones, just some of the most common.

Increased thirst and increased urination are common signs of trouble, as is increased appetite with weight loss. All of these together may indicate diabetes, but these symptoms are common to a number of diseases, so a check up is needed.

I hope that helps and I wish you the best of luck with him.
-Kurt