OPINION OF THE COURT
CIPARICK, J.Defendants Charles and Mary Zambito own Cecil, a beagle-collie-rottweiler mixed breed dog that they keep as a family pet. Defendants customarily confined Cecil to the kitchen area, behind a gate, when they were away from home and when visitors came, because he would bark. On the night of December 31, 1998, 12-year-old Matthew Collier was a guest of the defendants’ son, Daniel. He had been to the defendants’ home on several previous occasions, and on that evening had been upstairs with Daniel and several other children. When Matthew came downstairs to use the bathroom, the dog began to bark. Mary Zambito placed Cecil on a leash and, when Matthew emerged from the bathroom, invited him to approach to allow the dog to smell him, as the dog knew him from prior visits. As the boy approached, Cecil lunged and bit Matthew’s face. There *446is no dispute that the dog’s attack was unprovoked. The parties testified at their examinations before trial that, to their knowledge, Cecil had never previously threatened or bitten anyone.
At Supreme Court, defendants moved for summary judgment to dismiss plaintiffs complaint for failure to state a cause of action. Specifically, defendants argued that plaintiff did not demonstrate that the dog had vicious propensities or that the defendants knew or should have known of the dog’s alleged vicious propensities. Plaintiff cross-moved for summary judgment on the issue of liability. Supreme Court denied both motions, finding that plaintiff established an issue of fact as to whether the defendants knew or should have known of Cecil’s alleged vicious propensities. The court held that defendants’ implied knowledge of such propensities could be inferred by defendants’ confinement of Cecil in the kitchen.
The Appellate Division reversed, on the law, finding that plaintiff failed to raise an issue of fact as to whether the defendants were aware or should have been aware of their dog’s alleged vicious propensities (299 AD2d 866 [2002]). The Court further found no evidence that Cecil actually had vicious propensities of the type that resulted in Matthew’s injury. Two Justices dissented and would have voted to affirm, finding that plaintiff raised an issue of fact as to “whether defendants knew or should have known of Cecil’s dangerous propensities and, if so, whether defendant was negligent in initiating the contact between plaintiffs son and Cecil” (299 AD2d at 868). We now affirm.
Discussion
For at least 188 years (see e.g. Vrooman v Lawyer, 13 Johns 339 [1816]), the law of this state has been that the owner of a domestic animal who either knows or should have known of that animal’s vicious propensities will be held liable for the harm the animal causes as a result of those propensities (see Hosmer v Carney, 228 NY 73, 75 [1920]; see also Restatement [Second] of Torts § 509). Vicious propensities include the “propensity to do any act that might endanger the safety of the persons and property of others in a given situation” (Dickson v McCoy, 39 NY 400, 403 [1868]).
Knowledge of vicious propensities may of course be established by proof of prior acts of a similar kind of which the owner had notice (see Benoit v Troy & Lansingburgh R.R. Co., 154 NY 223, 225 [1897]; see also 5A-5 Warren, Negligence in New York *447Courts § 5.04 [6] [2003]). In addition, a triable issue of fact as to knowledge of a dog’s vicious propensities might be raised—even in the absence of proof that the dog had actually bitten someone—by evidence that it had been known to growl, snap or bare its teeth. Also potentially relevant is whether the owner chose to restrain the dog, and the manner in which the dog was restrained (see Hahnke v Friederich, 140 NY 224, 226 [1893]; see also Rider v White, 65 NY 54, 55-56 [1875]). The keeping of a dog as a guard dog may give rise to an inference that an owner had knowledge of the dog’s vicious propensities (see Hahnke, 140 NY at 227).
In addition, an animal that behaves in a manner that would not necessarily be considered dangerous or ferocious, but nevertheless reflects a proclivity to act in a way that puts others at risk of harm, can be found to have vicious propensities—albeit only when such proclivity results in the injury giving rise to the lawsuit. But nothing in our case law suggests that the mere fact that a dog was kept enclosed or chained or that a dog previously barked at people is sufficient to raise a triable issue of fact as to whether it had vicious propensities.
The evidence submitted by plaintiff was simply insufficient to raise an issue of fact as to whether Cecil had vicious propensities that were known, or should have been known, to defendants. Cecil was kept as a family pet, not as a guard dog. Although the dog was restricted to the kitchen area, uncontroverted deposition testimony indicated that he was confined only because he would bark when guests were at the house. There was no evidence that Cecil was confined because the owners feared he would do any harm to their visitors.* There was no evidence that the dog’s behavior was ever threatening or menacing. Indeed, the dog’s actions—barking and running around—are consistent with normal canine behavior. Barking and running around are what dogs do.
The infant plaintiff testified that he had met Cecil on previous occasions and was not afraid of the dog. Although he testified that Cecil was “[v]ery wild” when he had seen the dog on those previous occasions, he later clarified that what he meant was that the dog “[r]uns around a lot, . . . [and has] a lot of energy.” The parties were also unaware of any prior incidents *448in which the dog had attempted to bite or attack anyone, and defendants had received no previous complaints about the dog’s behavior. Plaintiff herself testified that Cecil had always been “friendly.” The fact that the owner invited Matthew to approach the dog would seem to demonstrate that she did not conceive of the possibility that the dog would attack the boy.
Finally, plaintiffs are not unduly burdened by the requirement of proof that a defendant know or should know of an animal’s vicious propensities. Once such knowledge is established, an owner faces strict liability for the harm the animal causes as a result of those propensities (see Strunk v Zoltanski, 62 NY2d 572, 575-576 [1984]). This disposition does not entitle dog owners to an automatic “one free bite.” There could certainly be circumstances where, although a dog has not yet bitten a person, its vicious nature is apparent. In that situation, the owner’s success in keeping the dog confined or restrained in the past would not insulate the owner from liability. The behavior exhibited by Cecil in this particular case simply does not rise to that level and summary judgment was properly granted dismissing the complaint.
Accordingly, the order of the Appellate Division should be affirmed, with costs.
The dissent’s suggestion that one could “reasonably conclude that defendants confined Cecil to the kitchen because they were aware of a potential danger” is simply unsupported by the record (dissenting op at 450).