Definition of "wolfer"

I have observed that there are only two types of eaters in this world - pickers and wolfers.

1987, Kerry Cue, Hang On To Your Horses Doovers, page 13

If your dog's a wolfer, here's a tip to slow him down: choose a couple of smooth stones (make sure they are too big for your dog to swallow), wash them, and put them in your dog's dish with his food.

2011, Marty Becker, Your Dog: The Owner's Manual

Wolf pelts were worth plenty of money in the late nineteenth century, and the wolfers had an easy way of killing their prey.

2012, Peter Edwards, Michel Auger, The Encyclopedia of Canadian Organized Crime