I started givign my pup Salmon oil pretty early around 4 months and he had no issues. I am sure someone with more knowledge will stop by and answer that question. My best results have been from giving my babies. 1 tbls of coconut oil in the morning mixed in with thier breakfast and 1 tbls of fish oil at night mixed in with their dinner. They have very shiny and soft fur. Also if Tucker doesnt like the snout stick you can use coconut oil on his nose, paws and even skin issues. Its really good for them. Just make sure to get good quality organic coconut oil.