Does Massachusetts Give a Dog One Free Bite?

Almost everyone believes a dog gets one free bite. Massachusetts does not work that way. M.G.L. c. 140, sec. 155 makes the owner or keeper liable when a dog does damage to the body or property of a person, and the injured person does not have to prove that anybody knew the dog was dangerous.

Two elements, and that is the whole case in chief

Section 155 is a strict liability statute rather than a negligence rule. The elements are that a dog did damage to a person’s body or property, and that the defendant is the owner or keeper of that dog. Knowledge of a prior bite, notice of a vicious propensity, and fault in handling the dog are all absent from the list.

The statute also says “any damage,” not “bite.” A dog that knocks a cyclist down, or that destroys property, sits inside the same rule.

Owner or keeper

The two words matter. Liability under section 155 reaches the keeper as well as the owner, which is what brings in a dog sitter, a house guest watching the dog, or a relative who had the animal at the time. Where the owner or keeper is a minor, the statute puts liability on that minor’s parent or guardian.

The three statutory bars

Section 155 provides exactly three circumstances that bar recovery, measured at the time of the damage: the injured person was committing a trespass, was committing another tort, or was teasing, tormenting or abusing the dog.

These are statutory bars with their own case law behind them. They are not a comparative fault framework, and describing them that way misstates how they operate.

The under-seven presumption

If the injured person is under seven years old, the statute presumes the child was doing none of those three things. The burden of proving otherwise shifts to the defendant. That presumption is written into the section, alongside the liability rule itself.

What section 155 does not decide

The statute establishes who is liable. It does not set a dollar figure, and no general page can tell an injured person what a particular claim is worth. That depends on the injury, the treatment, the records and the insurance actually available, which is a conversation to have with a lawyer about real facts.