Hi Corinne,
I don't have a lot of direct experience with Carnivora, but their concept of using an entire carcass to make a raw food diet seems sound. It is the best way to avoid nutrient imbalances, such as between calcium and phosphorus. Looking at their chicken diet, the fat content is a little lower that some others on a dry matter basis, but still substantial, which may be all that is needed to drive the formation of lipomas. Whole food made from lean carcasses may be better for preventing lipomas.
Note that raw diets don't seem to work that well for Shao Yang disharmony patients, which tend to have more leaky gut, systemic immune hyperactivity, and dysbiosis. Shao Yang disharmony, in turn, is a common cause of cancer, suggesting these three biomedical factors may have an important role to play in tumor formation. If that is the case, raw diets don't particularly help. I don't think they particularly hurt either, but in these animals, sources of fermentable carbohydrates and soluble fiber are critical to help seal the gut, calm the immune system and correct dysbiosis. This can be achieved by augmenting a raw diet, or by using another diet that has them already included, such as some freeze-dried diets
Hope that helps?
Steve