Boulder, CO Animal Ordinances: Chickens & Livestock (2026)

Section 6-1-41(a) is absolute: no person may own or keep any swine, hogs, or pigs within the city, with no lot-size exception. Subsection (b) takes a different approach for larger livestock, allowing horses, goats, sheep, cows, llamas, burros, or other equine or bovine animals only where the owner has at least one-half acre of total lot area per animal, plus its young under six months of age; a resident with a one-acre lot could therefore keep two goats but not four. Chickens, ducks, and other fowl are not named in Section 6-1-41 at all, so the acreage rule and the swine ban do not reach backyard poultry; the animal chapter's only fowl-specific provisions are unrelated ones, including Section 6-1-14(c), which bans selling fowl younger than six weeks old (with an exception for lots of ten or more sold for commercial, agricultural, or scientific purposes), and Section 6-1-7(a)(2), which requires fowl to always have access to a clean water receptacle.

Because Section 6-1-41 lists no penalty specific to itself, a conviction for keeping swine or over-density livestock is punished under Boulder's general penalty in Section 5-2-4: up to $2,650 in fines, up to ninety days in jail, or both. Enforcement runs through the city manager's animal control function and any peace officer under Section 6-1-32.