Dhtoy's dad came to hang out tonight, and it was clear my dog just didn't like him. We finally thought they were doing ok, and then completely out of nowhere, caddie turned and bit him in the face. It broke the skin, although not deep. Bleeding, but just barely (he's on blood thinners thanks to a heart attack last year. If not for the blood thinners, I doubt he would have bled). What would you do in this situation? This has never happened before. She's got quite a bark, but has never bit anyone, and when she's uncomfortable, there's typically warning signs. But tonight there were none. Truly went from him petting her to her biting him. Would you consider putting her down? Additional training? Or just discipline her and move on?