Oh, boy...prescription diets. This is where my journey began.
One of my cats had a severe bout of FLUTD a couple of years ago. This cat is so gentle, good-natured, and uncomplaining that I had no idea what was happening until it was critical. He never even peed outside the litter box. I discovered the problem when he growled at me for touching his lower belly. This cat had never growled in his life. I took him to the vet immediately, and he was there for a week.
I left with a prescription for Science Diet, and instructions that the cat should be drinking plenty of water (4 cups a day!!!), as well as a strong suggestion that I feed this to all of my cats, so I didn't have to keep him totally isolated.
I hate Science Diet. I have always hated Science Diet, but I fed it anyway, for too long. Fat cats got fatter, and normal weight cats started gaining, too, as well as puking. I started looking for other kibbles that were "safe" for FLUTD cats. Tried another brand which, while it did not cause more blockages, was very expensive and gave my cats loose stools that I was assured were "normal." No thanks. Cat poo is not supposed to look like pudding.
Switched to Wysong Uretic. Still no blockages, but cats still getting fatter. At least they weren't puking anymore. Started cautiously mixing in Wysong Epigen, all the while obsessively checking the litter box every time anyone used it, to make sure they were peeing.
The only good thing I have to say about that is that some of the fat cats started slimming down a bit. They undoubtedly would have done so on wet food, too, but when I had offered it before, they didn't like it, and I tried more than once.
Then, wonder of wonders, about a week ago, they ALL decided they didn't want to eat that stuff anymore, and only nibbled or sniffed at it before walking away. I still had some canned food, which I offered to them when I realized what was going on. They devoured it, and have only wanted canned since that day.
And that is the backstory behind my marvelous, self-transitioning cats, AND my hatred for prescription diets.
A nice fringe benefit is that I have not had to wash my Pomeranian's bottom for several days now. Stupid kibble was giving him the squirts at least every two or three days, no matter what kind I tried.