Diet for a dog with renal issues

I have a senior dog who was diagnosed this morning with a heart murmer and kidney issues. My vet started him on Enalapril once a day for 2 weeks for the heart murmer (We will then decide if his dose of 2.5mg once a day is enough) and suggested Hill's K/D for his renal issues. On Sunday morning Woody had a small seizure and thus the trip to the vet this a.m.

Blood work was done and everything was normal with the exception of his BUN levels - they were " a little elevated." But his creatine levels were normal. I noted to the vet that Woody been drinking more water lately and wanting to go out more often - perhaps another sign that he is at the beginning of CRF.

I would appreciate input on a diet for my dog. I did purchase the Hill's K/D, but I am not sure I want to go that route.

Thank you.

Melissa