It's always best to check with a vet. Kitten food is higher in protein and if a cat is having kidney problems, high protein will speed up the disease process. From what I understand. So it's always best to check first just to be sure. And cats with kidney problems do lose weight and tend to look scrawnyOriginally Posted by april31
I have put older cats on kitten food for them to put on wieght but with so many problems that this cat has had not sure i would try with out a vet approval.