Pound for pound, fat has more calories than any other food source. There is no reason to limit this (other than GI issues with too high a fat diet). I wouldn't boil any meat you add to the diet as that tends to remove the fat and some of the nutrients - dumped out with the water. If you choose chicken, just oven roast it and add back the cooked out fat (most dogs love this and if no GI issues is a good source of calories.)
There are some that promote a low (no carb) diet when treating various cancers. It's very hard to keep weight on with this diet, but something to consider.
BTW, coming in the next several months, pet foods will have calorie content added to the labels. Good thing if you can calculate serving size :B
Doug, DVM
