I, too, read about the 'wonders' of raw feeding compared to Felix/MacDonalds so set about changing Percy to raw (which I prepared myself, but using a supplement for all the nutrients they need). He took to it straight away, loved it, couldn't get enough of it, so I made a large batch which I froze in 2-portion size bags. Then................Percy started to go bald!!! Just little patches - on his tail, on the top of his head, on his tummy......I took him to the vet (but was too 'chicken'
to tell them he was on a raw diet) and they were baffled. They did skin scrapes (for mites etc.), ruled out fighting (because of the lack of scabs/scratches & the locations of the baldness) and didn't know where else to go with it. Well, I came home and experimented with changing him back to Felix/MacDonalds and - you guessed it - all his hair grew back and he's never lost it again. Now, I'm not saying that every cat would have this reaction (obviously they don't, otherwise there would be no raw feeders out there) - but something about it obviously didn't suit Percy. However, I do occasionally give him raw chicken wings for his teeth (biscuits crunch down before they 'hit' the tartar at the top of the teeth) which he loves.
I would like to think I could feed him better quality food - but he's a Felix man through and through I'm afraid!