Use the same logic as applies to deadly force on a human.
"Nuisance" is not enough, but a large dog which cannot be disengaged while mauling a 6-year old is toast.
postscript: I note that Moderator has eliminated the offending/dangerous post. Good job and quickly done.
Last edited by Al Norris; January 15, 2012 at 10:53 AM.
Reason: cleared up reference to deleted post