Middlesex County Dog Leash Laws Rules (2026) — What You Need to Know

Massachusetts does not have a statewide leash law. Instead, leash requirements in Middlesex County are established by individual municipal bylaws adopted by each city and town. Most Middlesex County communities require dogs to be leashed or under voice control when off the owner's property, but the specific requirements vary.

At the state level, MGL Chapter 140, Section 157 provides the framework for addressing nuisance and dangerous dogs. Any person may file a written complaint with the local hearing authority alleging that a dog is a nuisance or dangerous. The hearing authority must investigate and hold a public hearing. Importantly, Section 157 includes breed-neutral protections: no dog may be deemed dangerous solely based on its breed or based on growling or barking.

A dog is not considered dangerous if it was reacting proportionately to protect itself or its offspring, if the person attacked was committing a crime, was provoking the dog, or had entered an enclosure where the dog was kept. After a hearing, the hearing authority may issue orders including requiring the dog to be muzzled, confined, or restrained on a leash, or requiring the owner to carry liability insurance of at least $100,000.

Under MGL Chapter 140, Section 157A, an owner who fails to comply with a dangerous dog order faces a fine of up to $500 or imprisonment for up to 60 days for a first offense, and a fine of up to $1,000 or imprisonment for up to 90 days for subsequent offenses. Owners have 10 days to appeal an order to the district court.

Animal control officers in each municipality are responsible for enforcing both local leash laws and state dangerous dog provisions. Dogs found running at large may be impounded and the owner assessed impoundment fees. All dogs over 6 months of age must be licensed annually with the city or town clerk under MGL Chapter 140, Section 137.