Ive heard its a touchy subject, but however, if you feel in someway you could possibly be harmed by the loose animal. Heres some stuff that I had found. Hope it helps.
"[O]ne is 'privileged to destroy an animal for the purpose of defending himself or third persons against harm threatened by the animal, (a) if its actions led him to know or reasonably believe that the animal would inflict such harm and (b) the destruction was reasonable in view of the gravity of the harm threatened and (c) the person reasonably believed the harm could be prevented only by immediate destruction of the animal." (Devincenzi v. Faulkner (1959) 174 Cal.App.2d 250, 254-5.)
The law of self-defense permits aggression only for the purpose of meeting aggression. It does not permit revenge killing. "It is not the dog's predatory habits, nor his past transgressions, nor his reputation, however bad, but the doctrine of self-defense, whether of person or property, that gives the right to kill." (State v. Smith (1911) 156 N.C. 628, 72 S.E. 321.) There is no legal justification that will protect a person for killing or injuring a dog that bit him or her at a prior time, if the dog presented no threat at the time of the killing or injuring.
In California, people have a statutory right to kill dogs that attack certain listed animals, and a common-law right to defend their other domestic animals from attack under most circumstances. Other states have laws that are similar in nature; however, the list of animals might be different, so the laws have to be read carefully.
California provides a privilege to kill any animal that is worrying, wounding or killing certain other animals. California Civil Code section 3341, subdivision 2, states that any person can kill any animal (including a dog) that is off the premises of the owner and is worrying, wounding or killing certain listed animals:
3341, subd. 2. Any person on finding any dog or dogs, or other animal, not on the premises of the owner or possessor of such dog or dogs, or other animal, worrying, wounding, or killing any bovine animals, swine, horses, mules, burros, sheep, angora or cashmere goats, may, at the time of finding such dog or dogs, or other animal, kill the same, and the owner or owners thereof shall sustain no action for damages against any person so killing such dog or dogs, or other animal.
The section [Civil Code sec. 3341] was not intended to, nor does it, abridge the common law right of a person to defend his domestic animals against the attacks of dogs, or to kill such dogs when the circumstances warrant the belief that his property is in peril. At the common law the justification for the killing was complete when it appeared that the dog was engaged in worrying and terrifying domestic animals in their own lawful enclosure, and where the necessity of the killing in order to protect the property was apparent." (Sabin v. Smith (1915) 26 Cal.App. 676, 678-9.)
The right to kill a dog or other animal that is attacking a domestic animal is not affected by consideration of which animal is more valuable. "The right to kill a dog found trespassing and endangering property is not affected by the relative value of the dog and the property being injured." (Sabin v. Smith (1915) 26 Cal.App. 676, 680.)
In some states it is legal to kill a vicious dog that is running at large. For example, the law of Alaska makes it legal to kill a dog if (a) it "has ever bitten or attacked a human being" when "unprovoked", and (b) is running at large:
Sec. 03.55.010. Killing of vicious or mad dog authorized.
Any person may lawfully kill any vicious or mad dog running at large.
Sec. 03.55.020. Dogs deemed vicious.
Any dog which when unprovoked has ever bitten or attacked a human being is considered vicious within the meaning of AS 03.55.010.
Heres the site I got the info from. Hope it helps.
DOG BITE LAW - Legal Rights of Rescuers Who Incur Dog Bites
