Fresh liver can help. Also try the Furminator Deshedding comb. I love mine.
Most pet stores sell a supplement for dogs. It comes in a log (it looks like a log of premade cookie dough) and comes in a bunch of favors: beef, chicken, etc. With a vegetable peeler, add a little bit to your dogs food every day. The package says to cut off an inch or so of the log with each feeding- THAT IS WAY TOO MUCH. just a little goes a long way. Plus, the meat stick tastes great, your dog will love it