Montana dog laws: leash, licensing, bites and breed rules

This is a general summary of Montana state law for dog owners. It is information, not legal advice. Reviewed November 2026.

Leashes and licensing

Montana leaves dog control to local governments. A county may regulate, restrain or prohibit the running at large of dogs by ordinance, may require a licence tag on the dog's collar, and may impound, sell or destroy dogs found at large contrary to its ordinances (MCA 7-23-2108). City and town councils may regulate or prohibit dogs running at large and may license dogs (MCA 7-23-4101 and 7-23-4102). A county that has adopted such rules may cover only part of the county.

Where a county or municipal licence applies, state law makes it unlawful to own, harbor or keep a dog over 5 months old, or let it run at large, without a collar bearing a licence tag. The collar and tag may be removed when the dog is under the immediate control of its owner or the owner's agent (MCA 7-23-101). A dog found loose without a valid current tag can be seized and impounded by a sheriff, police officer or other officer (MCA 7-23-102).

Rabies vaccination

When a possible rabies exposure involves a dog, cat or ferret, the state rule directs the local health officer to arrange for the animal to be observed for signs of illness during a ten-day quarantine (ARM 37.114.571). The state health rule says the observation takes place at an animal shelter, veterinary facility or other adequate facility. Dogs coming into Montana must have an official health certificate and a rabies vaccination, except puppies under three months (ARM 32.3.213). Ask your county or city animal control about local vaccination rules where you live.

Dangerous dogs and bites

Montana's bite statute is strict but limited by place. The owner of a dog that bites a person or service animal without provocation, while the person or service animal is in a public place or lawfully on private property inside an incorporated city or town, is liable for the damages. The dog's former viciousness and the owner's knowledge of it are irrelevant (MCA 27-1-715). A person is lawfully on private property if there for a legal duty or as an invitee or licensee.

There is no statewide graded dangerous-dog system. A county may, by ordinance, regulate, restrain, control, kill or quarantine a "vicious dog," licensed or not. The statute defines it as a dog that bites or attempts to bite a human without provocation, or harasses, chases, bites or attempts to bite another animal, including livestock, service animals and pets. A violation of such an ordinance is a misdemeanor (MCA 7-23-2109).

Breed-specific rules

The state dog statutes reviewed contain no breed-specific rule. The county vicious-dog definition depends on what a dog does, not its breed. Check local rules for any breed restrictions.

Tethering and cruelty

Montana has no statewide law that sets tether length or time limits for dogs. The general cruelty law covers knowingly or negligently failing to give an animal food and water, minimum protection from adverse weather, or necessary veterinary care, and tormenting, injuring or abandoning an animal. A first offense is punishable by a fine up to $1,000 or up to one year in county jail, or both. A second offense, or any offense of aggravated animal cruelty, carries a fine up to $2,500 or up to 2 years in state prison (MCA 45-8-211).

Where to check your local rule

Counties, cities and towns often set stricter leash, licence, number-of-dogs, barking and vicious-dog rules. Check the county or city animal control website or ordinance code. If a dog has bitten someone or been reported, talk to a lawyer or the animal-control office.