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

Colorado sets statewide rules for rabies, dangerous dogs and bite claims, and it lets counties and cities handle leashes and licences. This summary is general information about state law and is not legal advice. Reviewed November 2026.

Leashes and licensing

The state has no leash law of its own. The county commissioners of any county may pass a resolution to control and license dogs, which can require that dogs be under control at all times, define a vicious dog, set up a pound and provide for impoundment. Cities and towns adopt their own ordinances. If a county does license dogs, it may not issue a licence unless the owner shows a valid rabies vaccination certificate signed by a licensed veterinarian.

Rabies vaccination

Rabies vaccination is ordered locally. A local board of health may order dogs and other animals in its area vaccinated against rabies. A veterinarian may waive the order for medical reasons.

Health officials may require an animal that attacked or bit a person to be confined at the owner's expense.

Dangerous dogs and bites

Colorado treats dangerous dogs through the criminal law. A dangerous dog is one that inflicts bodily or serious bodily injury on, or kills, a person or domestic animal, shows tendencies a reasonable person would think may cause such harm, or is trained for or engaged in dog fighting. Owning one is a crime, with penalties that depend on the harm: a class 2 misdemeanor when a person is injured, a class 1 misdemeanor for serious injury, a class 6 felony for a second serious-injury offense, and a class 5 felony if a person is killed. A convicted owner can be ordered to confine the dog in an escape-proof building or enclosure with a warning sign, keep it leashed outside, microchip it, and tell others of the conviction. The court must order confiscation after a serious injury or a death to a person or domestic animal.

On the civil side, a person who suffers serious bodily injury or death from a dog bite while lawfully on public or private property may sue the owner for economic damages whether or not the dog had ever shown viciousness. A court may order a dog euthanized if the owner knew of its dangerous tendencies. The owner is not liable to a trespasser, when the property is clearly posted with a "no trespassing" or "beware of dog" sign, or when the person knowingly provoked the dog.

Breed-specific rules

Any city or county rule for controlling dangerous dogs may not regulate them in a manner specific to breed.

Tethering and hot cars

Colorado has no statewide tethering law. Its cruelty statute does cover failing to provide proper food, drink or protection from the weather and confining an animal in a vehicle in a cruel or reckless manner. A person who breaks into a locked vehicle to rescue a dog or cat is immune from civil and criminal liability for the damage if there is a reasonable belief of imminent danger of death or serious bodily injury, a reasonable effort to find the owner, a call to law enforcement or 911 before entry, and the person stays with the vehicle until responders arrive.

Where to check your local rule

Cities and counties often have stricter leash, licence, number-of-dogs and other rules than the state. Check your city or county animal control website or ordinance code. If your dog has bitten someone or has been reported, talk to a lawyer or the animal-control office.