10 county-level rules, plus city-specific rules for 2 cities in Boulder County, Colorado.
Verified from official government sources
Boulder County Land Use Code 4-516.E allows accessory chicken keeping by right in the agricultural and residential-agricultural zones. Building lots in the Suburban Residential (SR) district may keep up to eight hens; roosters are prohibited in SR. Larger zones use an animal-units-per-acre limit.
Boulder County Land Use Code 4-516.E
Building lots in the SR zone district are permitted to have as many as eight (8) hens. Roosters are prohibited in the SR zone district... For the F, A, RR, ER, LI, GI, and MI zone districts, the maximum number of animals on a parcel shall be determined by the animal units allowed in that zone district.
In unincorporated Boulder County, dogs off the owner's property must be under leash, voice, or electronic control. Ordinance 2022-8 makes it unlawful to let any dog run at large; a dog is presumed at large if it causes injury, damage, or trespass.
Boulder County Ordinance 2022-8, Section 6(a)
It shall be unlawful for the owner of any dog to fail to prevent the dog from running at large in the entire unincorporated area of Boulder County. Any dog off the owner's premises... shall be under control as defined in Section 2 above, inside a vehicle or similarly physically confined so that said dog is without access to passers-by.
Boulder County has no breed-specific dog ban. Colorado state law (C.R.S. 18-9-204.5) regulates dangerous dogs by behavior, not breed, and C.R.S. 18-9-204.5(5)(b) bars any local regulation that is specific as to breed. The county handles risky dogs through its vicious-dog process.
Boulder County Ordinance 2022-8, Section 2(y)
"Vicious Dog" means a dog that has bitten or attempted to bite any person, without provocation, or has bitten a domestic or wild animal without being attacked or threatened with attack first. This definition applies to any dog even on the first bite or attempt regardless of any prior history.
Boulder County Land Use Code 4-516.D permits accessory beekeeping by right in the F, A, RR, ER, SR, LI, GI, and MI zones. It is an Open Agricultural use. In the Suburban Residential (SR) zone, two colonies are allowed per building lot (a queen and her workers count as one
Boulder County Land Use Code 4-516.D.5
Beekeeping is an Open Agricultural use. Two (2) colonies are allowed per building lot in the SR zone district. (A queen and her worker bees are considered one colony.)
Boulder County's animal ordinance covers dogs, cats, ferrets, and livestock but sets no separate exotic-pet permit. Ownership of exotic and wild animals is governed by Colorado state law: Colorado Parks and Wildlife rules bar keeping most native and dangerous wildlife without a state license.
Boulder County residents may not intentionally feed big game or bears. Colorado Parks and Wildlife regulation and C.R.S. 33-6-131 make it illegal to intentionally feed big game (deer, elk, pronghorn, bighorn sheep, mountain goats) and prohibit leaving food that attracts bears and lions. Boulder County promotes bear-resistant trash.
Boulder County Ordinance 2022-8, Section 6(b)
It shall be unlawful for the owner of a dog to allow such dog to chase or attack any person, domestic animal or fowl or any species of wildlife.
Boulder County limits livestock by 'animal units' per acre set in the Land Use Code zoning tables. Agricultural (A) land allows up to four animal units per acre without Special Review; most other rural zones allow two. Residential zones (RR, ER, SR) allow up to four weaned animals.
Boulder County Land Use Code, Article 4 (A / SR district standards)
Animal units... Four animal units per acre without going through Special Review [Agricultural district]... Residents in the SR zone may keep up to 8 hens and 2 bee colonies for their own use.
Boulder County has no separate 'hoarding' ordinance, but Ordinance 2022-8 makes it unlawful to fail to provide any livestock or domestic animal with minimum care, or to neglect, mistreat, or abandon an animal. Neglected animals may be impounded, and cruelty is prosecutable under Colorado state law.
Boulder County Ordinance 2022-8, Section 10(c)
Improper Care and Treatment. It shall be unlawful for a person to fail to provide any livestock or domestic animal with minimum care or to neglect, mistreat or abandon such animal.
Boulder County's animal ordinance sets no flat cap on the number of dogs or cats per household in the unincorporated area. Instead, keeping many animals is regulated indirectly through nuisance, barking, cruelty, and Land Use Code kennel/animal-units rules.
Boulder County Ordinance 2022-8, Section 9(c)
Habitual Offender. It shall be unlawful for a dog owner to violate any section of this Ordinance three or more times in any two-year period.
Boulder County's leash and at-large rules apply only to dogs, not cats. Cats are, however, covered by the mandatory rabies rule: Ordinance 2022-8 requires every dog, cat, and ferret to be vaccinated against rabies. A biting cat may be impounded for a 10-day observation.
Boulder County Ordinance 2022-8, Section 3(a)
It is ordered by the Boulder County Board of Health that the owner of each dog, cat or ferret in Boulder County shall have such dog, cat, or ferret inoculated... against rabies at three (3) months of age, one year later and a maximum of every three (3) years thereafter.
2 cities in Boulder County have their own animal ordinances rules. Each link goes to that city's dedicated page with code citations.
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