The One Bite Rule in New York in New York, NY Vicious Propensity and What Notice Means

The rule is about knowledge, not about counting bites

Under the strict liability branch of New York animal law, an injured person shows that the animal had a vicious propensity and that the person who kept it knew or had reason to know about it. Collier v Zambito, decided by the Court of Appeals on February 17, 2004, defined that propensity as the tendency to do any act that might endanger the safety of persons and property in a given situation. The opinion also said in terms that a triable question can exist without any earlier bite at all, where a dog has been known to growl, snap or bare its teeth. So the phrase "one bite" describes an evidentiary habit rather than a statutory threshold.

Who counts as the keeper of the dog

Agriculture and Markets Law 108 supplies the vocabulary the rest of the statute runs on. Subdivision 15 defines an owner as any person who harbors or keeps any dog, and subdivision 10 defines harboring as providing food or shelter to a dog. Those two definitions matter more in a dense city than they sound. A relative who feeds the animal on alternate weeks, a superintendent who lets it sleep in a basement room, or an adult child living in a parent's apartment can all fall inside that language depending on the facts. Identifying every person who fits the definition early is what keeps a claim from being aimed at a single defendant who turns out to be judgment-proof.

What courts have refused to treat as notice

The reported decisions are unusually specific about behavior that does not establish knowledge. In Agro v Olivieri, decided April 10, 2024, the Second Department listed conduct within normal canine range: running around, pulling on a leash, barking at another dog or at passersby, barking at strangers and chasing animals. Barking when someone knocked at the door did not convert the animal into a guard dog, and a sore ear with a tendency to pull away when petted was not enough either. Slotnick v Chaikin, decided May 28, 2025, applied the same reasoning and rejected an unsupported claim that a dog was kept for protection, adding that the nature and severity of an attack does not by itself prove what the owner knew beforehand.

The one number the statute does attach to the dog

Agriculture and Markets Law 123(10) makes the owner or lawful custodian of a dangerous dog strictly liable for medical costs resulting from an injury that animal inflicted on a person, companion animal, farm animal or domestic animal. That provision does not reach lost earnings, scarring or pain, and it applies to an animal that meets the statutory dangerous-dog description rather than to every dog that has bitten someone. Subdivision 12 then says that nothing in section 123 limits any other claim available at common law or under another statute. Read together, the two subdivisions explain why a hospital bill and the rest of a claim travel on separate tracks.

How the question reaches a judge

Most of these disputes are resolved on a summary judgment motion under CPLR 3212(b), where the moving party must show entitlement to judgment as a matter of law and the opposing party must produce evidence raising a genuine factual dispute. That procedural posture is why affidavits from neighbors, porters, delivery workers and dog walkers carry weight out of proportion to their length. A single sworn account of an earlier lunge at a stroller in a vestibule can be the difference between a dismissed claim and one set down for trial, which is also why those accounts should be collected while the people who witnessed them still live in the building.

Where the rule stands after April 2025

The strict liability branch is no longer the only route. On April 17, 2025 the Court of Appeals decided Flanders v Goodfellow and overruled Bard v Jahnke to the extent it barred a common-law negligence claim for harm caused by a domestic animal. An injured person in Manhattan may now plead knowledge of a propensity, ordinary negligence in how the animal was kept or handled, or both theories together. Guides and summaries written before that date describe New York as a jurisdiction where the propensity showing is the only path, and that description is now out of date.