Cotton wool coat

I have a three-year-old neutered Golden Retriever.
Even though he is fed a good diet, his coat is like cotton wool!
I wondered if anyone could suggest anything to make it more silky and shiny - but not too high in calories as that is an issue also!

Thanks

Wendy, via email 

Keeping glossy

Dear DT readers

What natural remedies or supplements do you use to keep your dog's coat looking healthy and shiny? Can you suggest any products that you particularly like?