Have been searching through old threads showing a lot of diverse opinions on this subject. Wondering what is the difference between fish oil for dogs and fish oil for humans? I want to treat arthritis from an old injury in a 9 year old and try and protect a 7 year old's joints. Do not have a coat or skin issue. I take krill oil which is expensive and am not sure how much difference it makes to my joints! It seems fish oil plus vit E might be the answer?