I laugh when I see that (a tiny little dog barking his head off at a big dog). Last week my landlord and I were talking on the stairs.... his dog, a big Lab was pouncing up and down the stairs. KiKi, my little cat, saw him and didn't like that he was bouncing around. She charged at him, ready to do battle. I got myself in between them just in time ... she's little but she would've done some damage.