YoungAgain cat food, huge recommendation
My cat has had IBD (or what they call that) for 8 years. She has had to be on prednisolone for that long.
We tried EVERYTHING over the years. The specials diets (hills/royal canin), special proteins (and strict no other foods), switching litters, water filters, etc. Nothing worked.
We found food that she was able to be 'stable' on while taking the pred - other foods would make her sick even on the pred. She is able to hold certain treats while on the full dose of pred.
On a whim of a cat food buying spree for my sweet little other cat who had pancreatitis and we were trying to get any food that she might eat - I bought YoungAgain pet food, and accidentally got their diabetic bag (I was not paying that close attention, panic buying).
My other cat would not eat it, so I started giving the food to my IBD cat as treats. I noticed her stools firmed up, and she was puking less. Her stools were a darker color, so I associated that with the YoungAgain pet food.
I have fully transitioned her now to the YoungAgain pet food, and it's going so well we are working with the vet to transition her off the pred. She isn't able to hold down treats any more - but that's okay, she can have the Young Again cat food as little treats. We also supplement with once-daily Koha Rabbit wet food, which I have mixed feelings about but she seems to like, and helps keep her water intake up.