
Being a Norwegian I swear by Kelp and use it in a multitude of ways, from politices to supplements..
However having a breed susceptible to Hypopigmentation, "Snow nose' I know that it doesnt work for all dogs.
Ive heard good things about Vit E (there's a good article in the BMJ)
Vitamin B complexs with choline
and just recently a good friend of mine has had fab results in 2 of her sibes using Dorwest Herbs 'Organic elderberry & nettle extract'
HTH and gives you some more ideas :)