Wendy

I have been reading alot on this site and have also been searching the web looking for ideas on what to feed Tanner as he battles cancer. I have switched him to grain free hi protein dry food along with fresh vegetables such as carrots,green beans,lettuce, and brocoli. The problem is, he is gaining to much weight and seems hungry all of the time. I have cut back the amount I feed him but he acts like he is starving at night. Any suggestions would be geatly appreciated. Maybe I am worrying to much about his weight since the cancer is the biggest concern. I just want him as happy as possible for the time he has left while helping his system in its battle.
Any thoughts on rawhide bones? Are they bad for dogs with cancer?