Salmon Oil is great for dogs. A tablespoon a day for large breed (Goldens) and half for smaller breeds.
It improves skin and helps prevent "hot spots", improves coat sheen, increases immunity to infection, increases bone strength. High in Omega and fatty acids it's recommended by several vets I know and my daughter in law has had great success with it for her three Goldens.
Can be ordered online at http://www.thewholisticpet.com or by phone at 1-888-452-7263 for credit card orders.
I have no connection with this company - I just send along the info for consideration of the Dog People aBoard.
Check with your vet ... you know, like they say about people medicine check with your doctor. Some Vets will say "It can't hurt" and it might be worth a month's try for your furry friend.
Would be interested to hear from anyone - via PM - who tries it.