The Wolves/Wild Dogs in Harvest Moon SNES are never seen by you, the hero, but they do appear in the night while your character sleeps. If you leave your cows or chickens outside at night, there is a high chance that the wolves will scare the cows or eat your chickens, so be sure to bring your animals in at night. There is also a chance that they will break down your fences at night, but if you leave your dog out, he will scare them away.