Dogs, just like us humans, tend to get dry skin specially during Winter. There are many things that I could recommend such as: changing his food, running a humidifier, making sure he is drinking enough water, etc. to avoid dry skin, but do you know what? This is the one thing, above all, that will keep your dog from having dry skin: brushing him once a day, at least. Yes, that’s it! Brushing him once a day. Very simple.
allmycaninecompanions 
Massage is also good at distributing skin oils to combat dry skin. If you were in New Zealand, you could attend one of my workshops for dog owners to learn a massage sequence for wellness. Best to check what courses are available in your area!
Message too! Totally.