My one cats eating habits have changed and I'm not sure if I should be worried

Does it mean anything if my cat has totally lost interest in treats (which he used to love)? He still seems to eat wet food ok and I'm pretty positive he still eats some dry food on occasion.

His sister still loves the treats and will gobble them down like there is no tomorrow. When I give them both some he will sniff them and walk away while she eats her pile then runs over to eat his.

He used to be every bit as greedy for a treat. I don't believe I had over fed them treats they would get a few a day. Since he stopped eating them I have tried several flavors from his favorite brand. Then when that didn't work I bought several different brands. I tried crunchy ones (which used to be what he loved), then moist, tried freeze dried meats, organic treats, and basically everything else on the shelf in the "treat" section of the pet store.

I know they are just treats and he is still eating normal food so I shouldn't be very concerned but it is a total change in his attitude. He also used to run to the food bowl when I would feed them and now he doesn't really seem to care unless I pick him up and carry him over or just wait 30 minutes to an hour then he'll eventually wonder over and eat.

So it's more of his attitude that worries me. Things he loved he doesn't seem to care about. (But he'll still play fetch, chase bugs, stare out the window for hours, cuddle in bed when I watch tv, etc. So a lot of him is the same but a lot has changed too)

When a cat changes it's behavior like that, the first thing to rule out is an underlying medical issue.  It's promising that he's still eating but it would be best if you could take him to the vet.  I don't know what it might be.  I once had a cat with mild kidney disease who lived to be 19 but who would periodically go off his food and turn down his treats.  The main thing is that you want to make sure you don't allow him to stop eating all together as fatty liver disease can set in, which is a very serious illness.  Best to nip it in the bud now.  Good luck!

My female cat is not interested in food much in this hot weather.

bonepicker it's not really a heat thing because he's been like this for a couple months. I've just been getting more worried about it because he'd always go crazy for his food like always and it's been more lately he watches me prepare it and just lays in the other room and watches his sister eat now. I literally have to pick him up and carry him to the bowl to get him to start eating and even then half the time he just walks away. And won't come back to eat for an hour or maybe more. Sometimes I have to lock his sister upstairs and him down just to make sure he actually eats his food and it's not just her pigging out.

I put a dry food bowl right by my side of the bed so if I hear someone eating I can see who it is that's the only way I know he will eat dry food on occasion, but it's not often.

Is he pooping and peeing regularly?   Does he struggle to poop at all?

I agree that a change in eating habit could be a medical issue.   Or maybe he's just bored with the food.  Do you feed them a variety of flavors, brands?

For piece of mind might be time just to get him a check up at the vet. 

lokhismom as far as I can tell he is fine in the littler box. And I have tried a wide variety of brands, flavors, and textures.

Over all he hasn't had any real change any other behavior that has been noticeable except being a little more skiddish around new people but he has been like that since we moved a little while back and I sorta attribute it to that. When anyone comes over he just runs to the upstairs bedroom and hides. While his sister will stay in the area but cautiously away from everyone. (And it used to sorta be the other way around).