Your vet appears to be of an old-fashioned school regarding kidney failure
. It's not so much the protein that is the problem. Protein does not cause kidney failure
, and many studies show that protein doesn't really make things worse. You do want to use more digestible forms of protein like scrambled eggs (use about 1/2 of the yolk), yogurt, or dark poultry meat. These proteins are higher in fats, but at this point the most important thing is to get your dog to eat something. Anything!