I have had some training in taking on dogs, it's a toughie, that video above just would not work, in kicking range the dog is already flying towards your chest or upper arm. You should assume that the dog has latched onto you. Crush chest/ribs with your superior weight if you can. He will likely be wriggling around on the end of your arm, so drop onto him if you can and destroy his ribs/chest with elbows or whatever. Finish him by "breaking the wishbone". Stand on one of his legs and lift his other leg with a strong jerking pull. Large mammals, well generally you are screwed, they do say that several people have been released by crocs etc by going for the eyes......