What loky1179 said above is very true guys (and gals). The vast majority of the times I've had to use force against a dog (usually not lethal force, that is the last resort) has been to defend my live-stock. The few times I've had to defend myself and once another person from a dog are the extreme minority and all of them were dogs that were taught by their owners to be vicious. Bad dogs are like bad kids, very few of them are truly bad seeds that are bad in and of their own, most of them have bad owners/parents any bread of dog can be made vicious by a bad owner but usually people who are of that bent choose breeds that are more dangerous and more easily made vicious just like their owners.
I'm no Bible thumper but some of the ancient laws of long ago that weren't religious in nature but civil and criminal made a whole lot more sense then our current laws including some of the ancient Hebrews, if I may quote one:
Originally Posted by NAS Bible Exodus 21:28-29
If an ox gores a man or a woman to death, the ox shall surely be stoned and its flesh shall not be eaten; but the owner of the ox shall go unpunished. If, however, an ox was previously in the habit of goring and its owner has been warned, yet he does not confine it and it kills a man or a woman, the ox shall be stoned and its owner also shall be put to death.
I think you get the principle of the thing that several thousand year old law was trying to put forth. I really wish that when it came to dangerous vicious aggressive dogs they would apply that same kind of logic today.