One of my retrievers bit me once when I tried to take a piece of meat from him that he found in the trash.
I took one step back, as he had gone back to chowing down, I clocked him squarely on top of the head with everything I had.
I broke a knuckle but he never did that again. Ever.
I had a collie when I was in HS. Gave it some leftover ribs one night. Neighbors german shepard came over and ran my collie off and started chowing down. Tried to take the ribs away and the fricker went for my throat, missed and bit me in the chest.
I backed up a minute while the shep went back to eating. Came up behind it, grabbed him underneath from the back, picked him up and slammed the frick out of him on the concrete. Tried to get a stomp in on his head but he recovered fast and took the frick off.