My brother works for the phone company and they have mace for dogs, one day he was out of mace and only had some hornet spray with him. This dog come after him and he sprays the dog in the face and he said it was like he shot the dog with a flame thrower, dog went nuts shaking its head and howling for about 5 minutes. They next day he had to back to finish the install and when he pulled up here comes the dog again until he seen who it was and turned and hauled a$$ the other way.