Bless him! If its the same as human kidney defects, he might be ok?! My kid suffers from a kedney defect where her right kidney is enlarged and the tube which joins into it is very tight which causes quite alot of U.T.I's...but you get to know the signs and catch it in plenty of time. Here's hoping its the same in cats ! My fingers are crossed for you and your buddy and I hope he gets well soon xxx