You are so right - dogs do not have to die from cancer. In the Yahoo group that Luella May and I host we found so many people who had pets, primarily dogs, with cancer that we ended up creating a sister forum. We have found that the same kind of things that work for humans also works well in many instances for dogs. In particular, colloidal silver is very good at eliminating fatty tumors and oleander and inositol/IP6 are effective against a variety of canine and other animal cancers, especially when combined with an anti-cancer diet (mostly raw mostly meat with some healthy additions in the case of dogs) and avoidance of toxins.
Speaking of toxins, dogs don't have to get cancer either the same as people - but often times they have even more to cope with than we do, what with having drinking water dispensed through PVC hoses and exposure to all kinds of yard pesticides, herbicides and other household toxins, and the decidedly unhealthy cheap dog foods you get at most grocers and other outlets.
In case you are interested, this is the kind of protocol we recommend: