I don't think a dog will give you that long. An agitated animal is incredibly fast and dangerous. Going hand to hand with a vicious dog, even with a blade, is risky business. Certainly a blade is better than nothing but not nearly as good as a firearm.
Lol, that was not what is was talking about,Ethe other poster said it was hard to get the dead dogs mouth off, which I don’t believe. However, I can guarantee you that with the first pass of a sharp knife the dog will lose all desire to bit, he has a really hard time breathing blood from that point on.