Denver
Protection Dogs

Denver does not wait for an injury. Under section 8-61 it is unlawful if an owner’s dog attacks or bites, and the code’s own definition of “attack” includes behavior that “confines the movement of a person,” with “chasing, cornering, or encircling” as examples and no contact needed. The one defense written for the owner’s residence needs a sign at every entrance and a dog that is truly confined. Owning a “dangerous animal” is flatly unlawful, a “potentially dangerous” label comes with a permit, and every dog over six months old must be altered unless an exemption or an annual intact permit applies.

None of these texts settles where a trained family protection dog falls in them. Whether such a dog is “dangerous” or “potentially dangerous” in Denver, or a “guard dog” in Cherry Hills Village, is a question for the city and a Colorado attorney, and this page asks it rather than answers it. Trainers wrote it, not a Colorado attorney or an insurance agent, so read it as a guide to the questions, not as advice. Every quoted passage is linked and was read at its source on 14 October 2026.

Start with the road. Our own query to the open-source OSRM routing engine on 14 October 2026, downtown Dallas to downtown Denver, returned about 795 miles and 14 hours 20 minutes before weather or stops; treat them as figures we computed, not a published table. How we hand a dog over, in person and in the home where it will live, is on our Colorado page, and it is the same for a fully trained dog or a puppy from Build Your Own Pup. This page quotes no delivery time or price.

Denver’s clocks start at acquisition. A dog over six months old that is “purchased, obtained, or otherwise acquired” must be licensed within thirty days under section 8-46, and a younger one has thirty days from reaching six months. Section 8-31 gives a person who “acquires within the city a dog” thirty days to have it vaccinated for rabies, and under section 8-32 the owner of an imported dog that stays more than thirty days must give the city proof of a current rabies vaccination. Which of the two covers a dog handed over at a Denver address is a question for Denver Animal Protection. These offenses, with spay and neuter, sit in the code’s class 4 list: up to $300, ten days in jail, or both, under section 1-14.

Colorado’s entry paperwork for a dog from Texas is not stated here because we could not read the state’s rule at its source. Section 8-71 requires animals brought into the city to comply with the state’s handling rules, so ask the Colorado State Veterinarian’s Office, and see our guides to buying out of state and flying.

Section 8-61 is a municipal offense in its own right, separate from any civil claim: section 1-13(a) declares a violation of any section that makes an act unlawful a criminal violation, with listed exceptions. Section 8-61 makes the owner or keeper “liable pursuant to this Code for the behavior of such animal,” and makes it unlawful if the animal attacks or bites a person or another domestic animal off the owner’s premises, on the owner’s residential premises, or in a business open to the public. An attack is “violent or aggressive physical contact,” or “violent or aggressive behavior that confines the movement of a person.” Contact is not required, which is the sentence the handler of any bite-trained dog should read twice. Our reading, and only that: the text writes no intent element into the offense, and the defenses are the ones it lists.

At the owner’s residence the list opens with a two-part defense. The premises must be “previously posted at each entrance” with a sign in letters “not less than two (2) inches in height,” and the animal must be “securely confined indoors” or kept in a secure enclosure under section 8-2(23): “suitable to prevent the entry of children age ten (10) and under,” escape-proof over and under, sheltered, and one that “Complies with the Denver Zoning Code.” Either half alone is not what the paragraph describes. How Colorado’s civil bite statute treats a sign is on our Colorado page; this is a different rule with its own test.

The other defenses are raised after the fact: the victim made an unlawful entry into the dwelling or into a vehicle holding the animal, provoked or tormented it, or used or seemed about to use unlawful force against the owner or another person. Separately, subsection (c) says the section does not apply to an owner whose animal attacks or bites someone who is physically attacking or striking that owner. The listed defenses carry into the dangerous-animal sections below, and none is permission for a dog to act.

Sections 8-61 to 8-63 state no fine. Section 1-13(b) sets a general penalty of up to $999, 300 days in jail, or both where “no definite fine or penalty is provided” and section 1-14 does not provide otherwise, and it caps an offense that matches a state offense at the state penalty. Section 1-14’s class lists, which are “not limited to” the names given, do not name these three sections, so which penalty applies is for a Denver municipal defense lawyer. Under section 8-66 the county court may also order the animal confined, removed from the city, or given “other dispositive action.”

Under section 8-62 a “dangerous animal” is one that has “caused serious bodily injury to any other person or domestic animal,” or “behaves in a manner that would have resulted in such serious bodily injury” but for “physical intervention by a person.” “It is unlawful to own any dangerous animal within the city,” with no permit path. Serious bodily injury, defined in section 8-2(25), includes a substantial risk of death or lasting disfigurement, and “breaks, or fractures.”

A “potentially dangerous animal” under section 8-63 is one that causes injury “less than serious bodily injury,” or, “without provocation,” approaches someone “in a menacing or terrorizing manner” off the owner’s property, or attacks a person lawfully on it, meaning one there on a legal duty or by “express or implied invitation.” Such a dog may stay only on a section 8-64 permit: one per household, microchipped, open to inspection “at any reasonable time,” with notice to the city within eight hours of an escape or an attack. At the agency’s or court’s discretion the permit can also require a secure enclosure, a warning sign, and a muzzle and six-foot leash outside. After thirty-six consecutive months without complaints the owner may ask to be declassified, “in the sole discretion of Denver Animal Protection.”

Under section 8-121, an owner who has reason to believe the animal bit someone enough to cause an abrasion of the skin must “immediately notify the executive director” and restrain the animal on the owner’s property. The Denver Animal Shelter’s FAQ says a pet that bites in Denver is quarantined for 10 days from the date of the bite and that each case is handled differently.

Nothing in sections 8-61 to 8-64 mentions training; their triggers are behaviors. Whether the city would count a bite on command, or a dog’s reaction to someone it takes for a threat, as any of them is a question for Denver Animal Protection and a Colorado attorney. We do not answer it, and no seller should answer it for you.

Section 8-55 makes it unlawful “to own or keep in the city any dog or cat over the age of six (6) months” that “has not been spayed or neutered,” except as section 8-56 allows. Section 8-56 lists four exits: a veterinarian’s written statement of an extreme health condition; an animal “temporarily in the city” for “a show or event sponsored by a sanctioned animal organization”; one kept in the city “fewer than thirty (30) days in a one-year period”; or an annual permit. The permit issues only if the dog is current on rabies and “is not housed with another intact animal of the same species and opposite sex in the same household,” the owner has had no more than two Chapter 8 violations in 24 months, a fee is paid, and the director finds approval “in the interests of the animal as well as the health and welfare of the public.” The shelter’s FAQ says to allow five business days.

The list has no exemption for a working, sport or protection dog, and whether a protection-sport trial counts as “a show or event sponsored by a sanctioned animal organization” is a question for Denver Animal Protection; we do not assume it does. When to alter a protection dog is a training and health decision before it is a permit one, and our guide to the male and female protection dog covers spay and neuter timing.

The Denver Zoning Code allows “3 maximum” dogs without a zoning permit, and no more than five dogs and cats together with no more than three dogs among them, kept as an accessory to a dwelling. On the dog count alone, a home with two dogs has room for a third; one with three needs the Zoning Administrator’s permit for a fourth, and section 8-8 makes keeping animals in breach of the zoning code unlawful without it. An outdoor kennel or exercise run is held to section 11.8.6: no more than 200 square feet, at least 20 feet from a habitable building on an adjacent lot, in the rear half of the lot, and screened from neighboring residential property by a solid fence or wall.

Those texts meet at section 8-61. Because the secure-enclosure definition requires compliance with the zoning code, an enclosure built to support the residence defense is a zoning question too. Our reading is that the zoning text does not say whether an ordinary fenced back yard is an “exercise run,” so ask Denver Community Planning and Development before building.

“Loose” is defined broadly as well. Section 8-16 bars letting a dog run at large, and section 8-2(22) counts a dog on its owner’s own premises if it is “confined in such a way as to allow the dog to have access to the public right-of-way.” Our reading is that a front yard open to the sidewalk fits. The exception is a designated off-leash enclosure, and a loose dog can be impounded without a complaint.

For a tenant, section 38-12-106 caps the extra pet deposit at three hundred dollars, refundable, and extra monthly rent at thirty-five dollars or one and one-half percent of the rent, whichever is greater. Our reading is that it sets money limits only and says nothing about which dogs a landlord may refuse.

Section 8-17 bars “loud and persistent or habitual barking, howling, or yelping” that disturbs a person or a neighborhood. Loud barking between 10:30 p.m. and 7:30 a.m., or “when none of the residents” are at home, creates “a rebuttable presumption that the dog barking was unlawful.” Under section 8-18, a dog with a conviction behind it and complaints from more than one household can be declared a nuisance and impounded after three to five days’ notice. Our reading is that loud barking that disturbs a neighbor while the house is empty, at a delivery driver or anyone else, falls within the second presumption. Cherry Hills Village’s thirty-minute rule is a different test, on our Colorado page.

Denver’s dog park rules turn away “aggressive dogs and dogs with a known propensity to attack or bite people or other dogs,” and allow only “activities common and customary for playing with, training and exercising dogs,” with no commercial use. Whether a dog trained to bite on command has a “known propensity” in that sense is not answered there, so ask Denver Parks before taking a working dog.

Cherry Hills Village is its own city with its own code, and section 7-5-30 defines a “guard dog” as one “used or trained for the protection of persons or property” by “attacking or threatening to attack any person found within an area patrolled by such dog.” Section 7-5-50(b) makes it unlawful to maintain one unless it is in a building, compartment or fenced enclosure, with a fence “at least six (6) feet in height” and no openings “with a diameter of more than two (2) inches”; on a leash “not exceeding four (4) feet in length” whenever it is out of that enclosure, held by an adult “physically able to control said dog”; and with signs “on all exterior building doors, gates and other entrances.” A loose guard dog “shall be impounded,” and the judge may not release it until the owner “has taken appropriate corrective action to ensure that the dog’s enclosure is escape-proof.”

Under section 7-5-610, a guard-dog violation requires a court appearance and a fine of at least $100, then $250, then $500 for each later one, and the owner is held to “strict liability.”

Whether a trained family protection dog is a guard dog in Cherry Hills Village is a question for the village’s animal control officer and a Colorado attorney, and we do not answer it: a dog that does nothing without its handler’s command may or may not be what “attacking or threatening to attack” was meant to cover. Our guide to guard dog versus protection dog uses the trainer’s meaning of those words; a municipal code is free to define them differently, and this one does.

The vicious-dog rule includes a defense that speaks to protection. A vicious dog is one that, “without provocation, causes bodily injury,” which the code defines as injury that results in “bruising, skin pain or any impairment of physical condition.” Defenses include a dog “protecting or defending a person within the immediate vicinity of the dog from an attack or assault.” A vicious dog is “subject to mandatory impoundment” where the victim suffered bodily injury, and a third violation for the same dog brings a destruction order.

The fence rule also meets the village’s zoning table, which for R-1 to R-3a caps a fence between the front lot line and the front façade at four feet and 50 percent opacity, and one within the setback from a lot line next to a public trail, park or open space at 40 percent opacity. The guard-dog rule itself says the fence “must be in conformance with the City’s Zoning Code.” Those caps and a six-foot guard-dog fence with two-inch openings are two texts to read together, and we draw no conclusion from them.

Aspen’s rules apply inside the city only; Pitkin County’s trail closures are on our Colorado page. Section 6.08.120 bans a vicious dog, one that “unprovokedly bites or attacks.” A bite on a person “unlawfully trespassing upon, breaking into or otherwise destroying or defacing” the owner’s property is “deemed to be provoked.” But a dog that attacked someone “merely trespassing” is not deemed provoked unless the owner has “clearly delineated the boundaries” by “a continuous obstruction” and posted, “in at least two (2) conspicuous places,” signs “at least four (4) inches by fourteen (14) inches in size.” Officers are to impound a vicious dog and may, if it cannot be caught safely, destroy it “without notice to the owner or keeper.”

Section 6.08.190 bans a harassing dog, one that “exhibits an apparent attitude of attack, approaches in a menacing fashion, chases a person or another animal,” and it is harassing “whether or not the offending dog inflicts injury.” Under section 6.08.050, “Dogs must be leashed on trails, sidewalks, streets and within the pedestrian mall,” one person may control no more than three dogs, and the owner answers for any contact with a person or animal, leashed or not.

Whether a dog that stops an intruder on its handler’s command is “vicious” or “harassing” is for Aspen’s animal safety officer and a Colorado attorney. The code does make plain that a warning sign in Aspen is measured in inches.

Each is a question the texts above raise and do not answer. An answer in writing from the office that enforces the rule is worth more than ours.

Also worth reading: the first 90 days, homeowners insurance, reading a demonstration, whether to buy one and our PSA decoy record.