There are so many different oil supplements I am not sure if any one is better then another. I think it will come down to price differences. I agree that your first step should be to check with the vet just how much oil is okay to give. Some vets carry supplemental omega oils, check if yours does and what they charge. A lot of people choose to buy the fish oil supplements from pharmacies, puncture the gel cap, and squeeze that onto the food.
"He is your friend, your partner, your defender, your dog. You are his life, his love, his leader. He will be yours, faithful and true, to the last beat of his heart. You owe it to him to be worthy of such devotion."