Honestly, it's a natural enough question - I think anyone who checks cat food on the internet will come away with the idea that certain ingredients are 'good', and certain are 'bad' - but, when it comes to your cat's health, I think the key thing is to work with your vet as well as conducting your own research. As I mentioned, the ingredients in the C/D didn't strike me as 'great' either - but I asked my vet and got a 10 minute talk about the how's and why's behind the prescription lines (yep, there's a reason for the pork in there).
And, honestly, the evidence will be how your cat is doing - and that's something you and your vet will also be checking regularly. In my case, my two are doing well, thank goodness - look good, act good, and pee well (happy dance!).
I just hope your cats do well going forward - nothing scarier than running to the e-vet with a cat that's not peeing - and hoping that you noticed in time!
And, honestly, the evidence will be how your cat is doing - and that's something you and your vet will also be checking regularly. In my case, my two are doing well, thank goodness - look good, act good, and pee well (happy dance!).
I just hope your cats do well going forward - nothing scarier than running to the e-vet with a cat that's not peeing - and hoping that you noticed in time!