In general, raw diets can be beneficial for dogs with cancer and most conditions, except if the cancer is in the bowel or liver or if the dog has a clinically expressed liver dysfunction. This is because bacteria in the food could multiply – especially if the contractions and relaxations (peristalsis) of bowel segments are irregular – thereby producing pockets of bowel stasis and promoting bacterial growth. The bacteria can then travel up the bile duct and further damage the remaining liver tissue.
For cases involving the liver or bowel, I suggest home cooking. One option is my Liver & GI Cleansing Diet.