OPINION OF THE COURT
Read, J.The accident underlying this litigation occurred on September *59427, 2001 at Hemlock Valley Farms in Otsego County, a dairy farm owned and operated by defendant Reinhardt Jahnke and his wife in partnership with their two sons. At roughly 8:00 a.m., plaintiff Larry Bard, a self-employed carpenter, arrived at the farm to meet defendant John Timer, another self-employed carpenter. One of Jahnke’s sons had asked Timer to repair ripped cow mattresses in a certain section—called the “low cow district”—of the farm’s free-stall dairy barn. This large barn, which was divided into several sections, housed approximately 400 cows at the time, 130 of them in the low cow district. The repair work involved chiseling off the bolts fastening the damaged mattresses to the concrete base of a stall, stretching the mattresses and then refastening the bolts. Timer had asked Bard the day before if he would be interested in helping him carry out this task, and Bard had replied that he would.
Timer, who had performed carpentry and odd jobs on the farm for about four or five years, walked Bard through the dairy barn, pointing out some of the projects that he had completed and where the milking parlor was. Timer took Bard to the barn’s low cow district, told him how to start the mattress repairs, and then left to complete another chore, planning to return shortly. Neither Timer nor Bard saw a bull; Bard testified that he saw no farm animals at all in the barn when he walked through it with Timer. From his previous work at the farm, Timer knew there was a bull at another barn about a quarter-mile distant from the dairy barn. Prior to Bard’s accident, he did not know that at all times there was a bull present in the dairy barn’s low cow district.
Bard retrieved some tools from his truck and started to work at about 8:30 a.m. He testified that a number of cows wandered into the area as he was working. Further, he was “familiar with working in and around cows,” which would “come up, drool on you, lick on you and everything else,” and that he didn’t “usually pay much attention to them.” At about 9:00 a.m., as Bard was down on his knees removing bolts, he first noticed a bull “[w]hen he stepped in behind him” and “bellered” within a distance of two to three feet. Bard testified that he “slowly kind of looked around, and didn’t know what to do at that point.” As he “went to stand up,” the bull “took [him] in the chest. [The bull] charged [him] then [and] proceeded to start slamming [him] into the pipes” in the stall. No one else was present in the low cow district at the time. Neither Jahnke nor anyone else associated with the farm knew ahead of time that Timer planned *595to repair the mattresses that day, or that Bard would be working for Timer to carry out this task.
Bard pulled himself outdoors through an opening at the bottom of the barn, and crawled over to his truck, where he lay for “quite awhile to get some wind and establish what was going on.” He caught the attention of someone working in the field, whom he asked to call an ambulance. Bard’s injuries included fractured ribs, a lacerated liver and exacerbation of a preexisting cervical spine condition.
The hornless dairy bull who injured Bard was named Fred. He was about IV2 years old, and had been the resident “cleanup” bull at the farm for at least six months prior to September 27, 2001. The cows and heifers on the farm are bred by artificial insemination. Fred was housed and roamed freely in the low cow district of the dairy barn so that he might impregnate cows stabled there who had failed to conceive by artificial insemination. Before this accident, Fred had concededly never threatened or injured any other farm animal or human being. As was the case with all the dairy bulls ever owned by Jahnke, a longtime dairy farmer, Fred was never chained, caged or barricaded within the barn. Prior to September 27, 2001, none of the bulls on any of the farms worked on or owned by Jahnke had ever acted aggressively toward, or injured, another farm animal or human being.
Bard, with his wife suing derivatively, commenced an action against both Jahnke and Timer to recover damages for his personal injuries, alleging causes of action sounding in strict liability and negligence. Plaintiffs subsequently moved for summary judgment on liability, and defendants cross-moved for summary judgment dismissing the complaint. Ruling on defendant’s cross motion,1 Supreme Court first observed that New York’s appellate courts had been “markedly consistent” in applying the common-law vicious propensity rule to decide whether owners of dogs and cats were liable for injuries caused by their animals. Citing Restatement (Second) of Torts § 518 and prior cases in the Appellate Division, however, the court concluded that a different rule applied to owners of domestic animals other than dogs and cats. According to Supreme Court, these owners are subject to “some duty of enhanced care” to restrain or confine the animal or to warn a human being who *596might come into contact with it. Applying this rule to the facts, Supreme Court granted defendants’ motions for summary judgment because Jahnke did not know that Bard would be at his farm or working in the dairy barn, and Timer was unaware of the cleanup bull’s presence in the barn.
The Appellate Division affirmed, but on a different basis altogether. Noting that a bull is a domestic animal as defined in Agriculture and Markets Law § 108 (7) and citing our recent decision in Collier v Zambito (1 NY3d 444 [2004]), the Court concluded that Jahnke was not liable for Bard’s injuries unless he knew or should have known of the bull’s vicious or violent propensities. The Court noted that the record contained no evidence of this, and “[t]o the contrary, it contains competent evidence establishing that, prior to [Bard’s] accident, the subject bull had never injured another person or animal or behaved in a hostile or threatening manner” (16 AD3d 896, 897 [3d Dept 2005]).
Bard had submitted the affidavit of a professor of animal science, who opined that “bulls, in particular breeding bulls, are generally dangerous and vicious animals,” and that therefore Jahnke should have restrained the bull or warned Bard of its presence (id.). The Court found this affidavit unavailing, especially in light of its “consistent[ ], and recently[ ] reiterated” view that “the particular type or breed of domestic animal alone is insufficient to raise a question of fact as to vicious propensities” (id. [internal quotation marks and citations omitted]).
Finally, with respect to Bard’s negligence claim, the Appellate Division noted that it had “considered and decline[d] to adopt the enhanced duty rule espoused under certain limited circumstances by the First and Second Departments” (id. at 898). Bard subsequently sought to appeal so much of the Court’s order as affirmed the grant of summary judgment to Jahnke. We granted him leave to appeal, and now affirm on the ground adduced by the Appellate Division.
Only two years ago, in Collier, we restated our long-standing rule
“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. Vicious propensities include the propensity to do any act that might endanger the safety of the *597persons and property of others in a given situation” (Collier, 1 NY3d at 446 [internal quotation marks and citations omitted]; see also NY PJI 2:220 [2006]).
Once this knowledge is established, the owner faces strict liability.2 We made two additional points in Collier, which bear repeating.
First, while knowledge of vicious propensities “may of course be established by proof of prior acts of a similar kind of which the owner had notice,” a triable issue of fact as to whether the owner knew or should have known that its animal harbored vicious propensities may be raised by proof of something less (Collier, 1 NY3d at 446). In Collier, a case in which a dog bit a child, we gave the example of evidence that a dog had, for example, “been known to growl, snap or bare its teeth,” or that “the owner chose to restrain the dog, and the manner in which the dog was restrained” (id. at 447).
“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” {id.).
Here, Fred had never attacked any farm animal or human being before September 27, 2001. He had always moved unrestrained within the limits of the barn’s low cow district, regularly coming into contact with other farm animals, farm workers and members of the Jahnke family without incident or hint of hostility. He had never acted in a way that put others at risk of harm. As a result, Bard cannot recover under our traditional rule.
Bard therefore argues alternatively that he can recover under a common-law cause of action for negligence, as expressed in Restatement (Second) of Torts § 518, Comments g and h. This common-law cause of action is, he claims, separate and apart from and in addition to our traditional rule.
*598Section 518 provides generally that the owner of a domestic animal, which the owner does not know or have reason to know to be abnormally dangerous, is nonetheless liable if he intentionally causes the animal to do harm, or is negligent in failing to prevent harm. Comment g, “Knowledge of normal characteristics” provides that
“[i]n determining the care that the keeper of a not abnormally dangerous domestic animal is required to exercise to keep it under control, the characteristics that are normal to its class are decisive, and one who keeps the animal is required to know the characteristics. Thus the keeper of a bull or stallion is required to take greater precautions to confine it to the land on which it is kept and to keep it under effective control when it is taken from the land than would be required of the keeper of a cow or gelding.”
Comment h, “Animals dangerous under particular circumstances” states that
“[o]ne who keeps a domestic animal that possesses only those dangerous propensities that are normal to its class is required to know its normal habits and tendencies. He is therefore required to realize that even ordinarily gentle animals are likely to be dangerous under particular circumstances and to exercise reasonable care to prevent foreseeable harm. Thus the keeper of even a gentle bull must take into account the tendencies of bulls as a class to attack moving objects and must exercise greater precautions to keep his bull under complete control if he drives it upon a public highway. So, too, the keeper of an ordinarily gentle bitch or cat is required to know that while caring for her puppies or kittens she is likely to attack other animals and human beings.”
Building on these provisions and their specific references to bulls, Bard contends that because Fred was not only a bull, but a breeding bull housed with the herd over whom he exercised dominance, Jahnke was negligent in failing to restrain Fred,3 or to warn non-farm personnel of his presence. But this is no dif*599ferent from arguing that Jahnke was negligent in that he should have known of Fred’s vicious propensities because—as plaintiffs’ expert put it—“bulls, in particular breeding bulls, are generally dangerous and vicious animals.” (16 AD3d at 897.)
As already noted, an animal’s propensity to cause injury may be proven by something other than prior comparably vicious acts. As a result, a common shorthand name for our traditional rule—the “one-bite rule”—is a misnomer. We have never, however, held that particular breeds or kinds of domestic animals are dangerous, and therefore when an individual animal of the breed or kind causes harm, its owner is charged with knowledge of vicious propensities. Similarly, we have never held that male domestic animals kept for breeding or female domestic animals caring for their young are dangerous as a class. We decline to do so now, or otherwise to dilute our traditional rule under the guise of a companion common-law cause of action for negligence. In sum, when harm is caused by a domestic animal, its owner’s liability is determined solely by application of the rule articulated in Collier.
Accordingly, the order of Appellate Division should be affirmed, with costs.
. Plaintiffs withdrew their motion for summary judgment at oral argument.
. Our rule is virtually identical to Restatement (Second) of Torts § 509 (1) (1977): “A possessor of a domestic animal that he knows or has reason to know has dangerous propensities abnormal to its class, is subject to liability for harm done by the animal to another, although he has exercised the utmost care to prevent it from doing the harm.”
. Fred was, of course, restricted to the low cow district of the barn. He was not, in any sense, “loose”: he neither escaped nor was he taken from the *599confines within which he was normally kept, and he was not driven upon a public highway, the specific situations referenced in Comments g and h, respectively.