Personal Injury · Dog Bite Liability

Dog Bite Laws in Massachusetts

Whether Massachusetts holds a dog owner automatically liable, follows the one-bite rule, or takes a mixed approach, plus landlord liability and the main defenses.

Official statuteRead word-for-word

against M.G.L. c.140 §155 · malegislature.gov

Read from the official source · Jul 8, 2026How we verify →

Dog-bite liability · Massachusetts

Strict liability

The owner or keeper is strictly liable for any bodily or property damage a dog causes, not just bites, without proof of negligence or knowledge, unless a statutory exception applies.

BasisStatute

CoversAny injury

Landlord liable?Rarely

StatuteM.G.L. c.140 §155

How liability works in Massachusetts

What the rule is, and what you must show.

What the victim must show

Any bodily or property injury counts (knocking someone over, chasing, or biting). A child under 7 gets a rebuttable presumption that they did not trespass or provoke, shifting the burden to the defendant.

Landlords & defenses

Who else can be liable, and what defeats a claim.

Landlord liability

Generally no: liability runs to the "owner or keeper," and a landlord is not automatically a keeper. A landlord can be liable if they actually keep or harbor the dog, or through common-law negligence with knowledge and control.

Main defenses

Victim was trespassing or committing another tortTeasing, tormenting, or abusing the dog

These are the only statutory exceptions. For a child under 7, the defendant carries the burden to prove them.

The full picture, with the source

Every field, and any recent development.

Liability model	Strict liability
Basis	Statute: M.G.L. c.140 §155
What it covers	Any bodily or property injury counts (knocking someone over, chasing, or biting). A child under 7 gets a rebuttable presumption that they did not trespass or provoke, shifting the burden to the defendant.
Landlord	Generally no: liability runs to the "owner or keeper," and a landlord is not automatically a keeper. A landlord can be liable if they actually keep or harbor the dog, or through common-law negligence with knowledge and control.
Main defenses	Victim was trespassing or committing another tort · Teasing, tormenting, or abusing the dog

What Massachusetts dog-bite victims get wrong

Massachusetts is one of the broadest strict-liability states: under M.G.L. c.140 §155 the owner or keeper is liable for any bodily or property damage a dog causes (not only bites, but also knocking someone down, chasing, or damaging property) without any proof of negligence or prior viciousness. The statute leaves only two exceptions: the victim was trespassing or committing another tort, or was teasing, tormenting, or abusing the dog. Massachusetts also protects young children: a child under seven is presumed not to have trespassed or provoked the dog, which flips the burden onto the defendant to prove otherwise. Landlords are generally outside the statute unless they truly keep or harbor the animal.

Common questions

Is Massachusetts a strict-liability dog-bite state?

Yes, and broadly so. Under M.G.L. c.140 §155 the owner or keeper is strictly liable for any bodily or property damage a dog causes, not just bites, subject to two narrow exceptions.

Does Massachusetts cover injuries other than bites?

Yes. The statute reaches any bodily or property damage, so being knocked down, chased, or having property damaged can all qualify.

What special rule applies to young children in Massachusetts?

A child under 7 is presumed not to have been trespassing or provoking the dog, so the defendant carries the burden to prove one of those exceptions.

What are the only defenses under the Massachusetts dog-bite statute?

The victim was trespassing or committing another tort, or was teasing, tormenting, or abusing the dog. There are no other statutory exceptions.

Primary source

→ M.G.L. c.140 §155

Massachusetts General Laws (c.140 §155) · malegislature.gov

Cholilurrohman
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