Massachusetts Dog Bite Laws: Liability and Victim Rights

Overview of Massachusetts Dog Bite Laws

Massachusetts is one of the strongest strict liability states in the country when it comes to dog bite injuries. Under M.G.L. c. 140, § 155, a dog's owner or keeper is automatically liable for any damage the dog causes to a person's body or property. The victim does not need to prove the owner was negligent or that the dog had any history of aggression.

This statute covers all types of dog-related injuries, not just bites. If a dog knocks someone down, scratches them, or destroys their property, the same strict liability standard applies.

The law places the burden squarely on dog owners. If you own or keep a dog in Massachusetts, you are financially responsible for any harm that dog causes, with only narrow exceptions.

The Strict Liability Standard: M.G.L. c. 140, § 155

The core of Massachusetts dog bite law is M.G.L. c. 140, § 155. The statute states that if any dog does damage to the body or property of any person, the owner or keeper shall be liable for such damage.

If the owner or keeper is a minor, the minor's parent or guardian becomes liable instead.

What Victims Must Prove

To win a dog bite case in Massachusetts, the victim needs to establish only three things:

1. The defendant owned or kept the dog
2. The dog caused damage to the victim's body or property
3. The victim was not trespassing, committing another tort, or teasing, tormenting, or abusing the dog at the time

Notice what is absent from that list. The victim does not need to show:

• The owner knew the dog was dangerous
• The dog had bitten anyone before
• The owner failed to use reasonable care
• The dog had shown aggressive tendencies

This makes Massachusetts far more favorable to dog bite victims than states that follow the "one-bite rule," where owners escape liability if they had no prior knowledge of their dog's dangerous behavior.

Who Qualifies as a "Keeper"

The statute imposes liability on both owners and "keepers." Massachusetts courts have defined a keeper as someone who harbors a dog and assumes custody, management, and control over it. Simply living in the same household as a dog, or merely allowing a dog on your property, is not enough to make someone a keeper.

This distinction matters in cases involving dog walkers, pet sitters, and other temporary caretakers.

Special Protections for Children Under 7

M.G.L. c. 140, § 155 includes a powerful provision protecting young children. If the victim is under seven years of age, the law presumes the child was not trespassing, committing a tort, or provoking the dog.

This shifts the burden of proof to the dog owner. The owner must affirmatively prove that the child was trespassing or provoking the dog in order to escape liability. In practice, this presumption makes it very difficult for dog owners to avoid responsibility when a young child is injured.

Legal Defenses for Dog Owners

The statute provides three specific defenses that can eliminate or reduce the owner's liability.

Trespassing or Committing a Tort

If the victim was trespassing on the owner's property or committing another tort at the time of the bite, the owner is not liable under § 155. However, the trespassing defense is harder to invoke against children under seven because of the presumption described above.

Teasing, Tormenting, or Abusing the Dog

If the victim provoked the dog by teasing, tormenting, or abusing it, the owner may escape liability. The provocation must be the direct cause of the bite. Minor interactions that would not cause a reasonable dog to bite typically do not qualify.

Comparative Negligence

Massachusetts follows a modified comparative negligence rule under M.G.L. c. 231, § 85. If a court finds that the victim's own negligence contributed to the injury, the victim's damages are reduced in proportion to their share of fault. If the victim is more than 50% at fault, they are barred from recovering any damages at all.

This means that even in a strict liability case, the victim's behavior leading up to the bite can reduce or eliminate their recovery.

Damages Available to Dog Bite Victims

Dog bite victims in Massachusetts can pursue both economic and non-economic damages.

Economic Damages

• Medical bills, including emergency treatment, surgery, and rehabilitation
• Future medical costs for ongoing treatment or reconstructive procedures
• Lost wages from missed work during recovery
• Loss of earning capacity if injuries cause long-term disability
• Property damage

Non-Economic Damages

• Pain and suffering
• Emotional distress and psychological trauma, including PTSD
• Scarring and disfigurement
• Loss of enjoyment of life

Massachusetts does not impose a statutory cap on damages in dog bite cases. The full extent of the victim's losses can be recovered.

Statute of Limitations

Dog bite victims in Massachusetts must file their lawsuit within 3 years from the date of the injury. This deadline comes from M.G.L. c. 260, § 2A, which governs personal injury claims.

Key points about the filing deadline:

• The clock starts on the date of the bite or attack
• If the victim was a minor at the time of the injury, the 3-year period does not begin until the minor turns 18
• Claims against municipalities or government entities may have shorter notice requirements, sometimes as short as 30 days
• Missing the deadline almost always results in permanent dismissal of the case

Dangerous Dog Designations: M.G.L. c. 140, § 157

Massachusetts has a detailed process for classifying dogs as "nuisance" or "dangerous" under M.G.L. c. 140, § 157. This process is separate from the civil liability statute but can result in serious consequences for dog owners.

How the Process Works

Any person may file a written complaint with the local hearing authority (typically an animal control officer or municipal official) alleging that a dog is a nuisance or dangerous. The hearing authority then investigates and holds a public hearing.

Based on credible evidence and testimony, the hearing authority can:

1. Dismiss the complaint
2. Deem the dog a nuisance dog
3. Deem the dog a dangerous dog

What Makes a Dog "Dangerous"

A dog may be deemed dangerous if it attacks a person or domestic animal causing physical injury or death without justification. However, the law includes important limitations. A dog cannot be deemed dangerous:

• Solely based on growling or barking
• Based on the dog's breed
• If the dog was protecting itself, its offspring, another animal, or a person from attack
• If the person threatened or attacked was committing a crime against the owner or keeper
• If the person was teasing, tormenting, or provoking the dog

Requirements for Owners of Dangerous Dogs

If a dog is deemed dangerous, the hearing authority may order the owner to:

• Confine the dog in a securely enclosed and locked pen with a secure roof, with sides embedded at least 2 feet into the ground if there is no secured floor
• Muzzle the dog securely and humanely when off the owner's premises, using a chain or tether with a minimum tensile strength of 300 pounds and no longer than 3 feet
• Maintain liability insurance
• Comply with any other conditions the hearing authority considers necessary

Statewide Ban on Breed-Specific Legislation

Massachusetts law explicitly prohibits cities and towns from regulating dogs in a manner that is specific to breed. No dog can be found to be a nuisance or dangerous based solely on its breed. This means breed-specific bans targeting pit bulls, Rottweilers, or any other breed are illegal throughout the state.

Criminal Penalties: M.G.L. c. 140, § 157A

Dog owners who fail to comply with a dangerous dog order face criminal penalties under M.G.L. c. 140, § 157A.

Offense	Maximum Fine	Maximum Jail Time
First offense	$500	60 days
Second or subsequent offense	$1,000	90 days

In the most serious cases, a court may order a dangerous dog to be euthanized. If euthanasia is ordered and affirmed on appeal, the owner must reimburse the city or town for all reasonable costs incurred for housing and caring for the dog during impoundment and throughout the appeals process.

Landlord Liability for Dog Bites

Landlords in Massachusetts are generally not considered "owners" or "keepers" of a tenant's dog under § 155. Instead, landlord liability for tenant dog bites is governed by common-law negligence principles.

A landlord may be held liable if:

• The landlord knew or reasonably should have known the tenant's dog had dangerous propensities
• The landlord had the authority to require removal of the dog (through a lease provision, for example)
• The landlord failed to take reasonable steps to protect others

Simply owning the property where a tenant keeps a dog does not create strict liability for the landlord. The injured person must prove the landlord was negligent.

Dog Owner Responsibilities

Beyond the liability statute, Massachusetts imposes several obligations on dog owners:

• Licensing: All dogs six months or older must be licensed annually with the city or town clerk (M.G.L. c. 140, § 137)
• Rabies Vaccination: Dogs must be vaccinated against rabies before licensing
• Leash Laws: Many Massachusetts municipalities have local leash ordinances; check your city or town's bylaws
• Confinement: Dogs must be kept under the owner's control at all times
• Reporting Bites: Dog bites must be reported to the local board of health

How to File a Dog Bite Claim in Massachusetts

If a dog has injured you or your property in Massachusetts, take these steps to protect your legal rights:

1. Get medical treatment immediately. Your health comes first, and medical records create essential documentation for your claim.
2. Report the bite to local animal control and police. This creates an official record and may trigger a dangerous dog investigation.
3. Document the scene. Photograph your injuries, the location, and the dog if you can do so safely.
4. Collect the owner's information. Get their name, address, phone number, and homeowner's or renter's insurance details.
5. Identify witnesses. Get contact information from anyone who saw the incident.
6. Preserve physical evidence. Keep torn or bloody clothing and any other items damaged in the attack.
7. Contact a personal injury attorney. Because Massachusetts is a strict liability state, an experienced attorney can evaluate your case quickly.

Remember that you have 3 years from the date of the bite to file a lawsuit, but starting the process early preserves evidence and strengthens your claim.

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