Originally Posted by floortje
He was eating only dry food, also from Royal Canin, for sterelised cats and it is a miracle that he was eating that at all.
Ah-ha! What I'm trying to get at is whether he really needs to be on the Sensitive Royal Canin formula (is it dry or wet?). There isn't anything magical about prescription foods, and in fact all of them have very poor quality ingredients. Likely just switching your cat to a better quality WET food would have helped with the vomiting, and now that he has renal issues, it's even more important that he be eating high quality protein with high moisture content. There is no vet food that fits the bill. Not sure what you have available where you live, but here in North America some of the better commercial foods are Wellness, Nature's Variety, By Nature, Weruva, Addiction, Merrick, Ziwipeak, Eagle Pack, Precise, Evangers.....