Help. Dog addiction to eating snow

We have a 4 month old lab puppy. From the day we got him he has been obsessed with drinking water, its literally what he lives for. Prefers it over food, treats, attention, and other dogs. We tried to quash it by giving him unlimited access to water only to have his stomach swell up like a bowling ball. He would drink until he peed constantly, threw up or both. We rectified this by regulating his water intake little bit every few hours.

Fast forward to the Canadian winter, he has figured out snow is just frozen water. We can't take him for walks, to the dog park or even out to pee without him devouring snow to the point his little body is shaking cold. We have tried disipline (tap on the nose, firm NO, pulling him away by his collar. Distraction, treats, everything. He does not respond to anything as his sole purpose and greatest love in life is to eat that snow. We can pull on his collar to the point his two front legs are off the ground and he does a little gag, the second we lower him back down its back to the snow. Pain, treats, dogs - nothing stops him.

At the dog park instead of playing with the others, he will find a patch of deep snow and feast until we drag (literally) him out of there. When we pull him away from the snow he'll fight, yelp, run and do everything to get one more bite.

Its very sad to see him like this and is affecting our lives and his. He young any chance he will just grow out of this?

Any help or insight would be greatly appreciated.

Take him to the vets.