If you really want the benefits of omega 3s for her coat and cancer fighting properties then you want to stay away from fish based foods and only add fresh or well protected sources or omega 3s. Omega 3s oxidize quickly when exposed to air and oxidized fats are more in the line of cancer promoting than cancer fighting. You are better off feeding a good food and adding omega 3 right before feeding.
Since you aren’t sure what size your pup will be, you should also read the first few pages of the Large and Giant Breed Puppy Nutrition thread in the Diet and Health Issues forum.
