Our 13 year old male tabby cat had two kinds of bladder stones a couple of years ago. He had surgery for the stones, all were removed, and there's been no issue with the stones returning since then. At the time of the surgery he weighed about 17-18 pounds. The vet recommended that we feed him Hill's Prescription Diet "w/d" dry food for digestive issues and weight management, and since then he's come down to about 13 pounds. As background info he's naturally a biggish, lanky cat.
I'm worried that he's getting too thin, even at 13 pounds. He's a solitary indoor cat (we live in NYC), so doesn't get a ton of exercise. The weather this summer (hot) seemed to take the wind out of his sails, even with the AC left on during the day when it's extremely hot. He's less interested in eating overall. This isn't to say he doesn't have an appetite, he just doesn't eat as much as he once did. I'm hoping that when the weather turns cooler his appetite will return. I supplement in fresh chicken and fish to give me a bit more fat, but even that he doesn't always go crazy for it the way he once did. I realize that he's getting older and he will shrink the way that most creatures do in their latter days.
As mentioned before we buy him the Hill's Prescription "w/d" food for digestive and weight management issues. Cleary the weight management isn't an issue anymore, but we do not want the bladder stones to return. The Hill's w/d food goes for about $65 for an 18 pound bag, which is a lot of money. Is there a cheaper option that will give him a bit more caloric intake while still keeping the digestive issues at bay?