A.You can add the omegas now. I prefer using fish, especially imported salmon oils. You can also provide a good vitamin/mineral supplement. One word of caution: I have seen dogs do well and live long, healthy lives on vegetarian diets, but they are ancestrally carnivores. So monitor the process and your puppy’s growth and health. To answer your last question, I have seen vegetarian diets improve skin problems, actually make them worse, or have no effect either way.