Boulder County, CO Animal Ordinances: Mandatory Spay/Neuter (2026)

Section 6(d) of Animal Control Ordinance No. 2022-8 targets only dogs that are both unneutered or unspayed and running at large: when an Animal Control Officer apprehends such a dog, the officer may issue a Penalty Assessment Notice at double the fine that applies to an ordinary Dog at Large violation. The Section 12(a)(4) penalty schedule spells out the numbers: an "Unneutered or Unspayed Dog at Large" costs $90 for a first offense, $180 for a second, and up to a $300 maximum for subsequent offenses, versus $45, $90 and $300 for a spayed or neutered dog caught at large under the same schedule.

Neither provision reaches a dog that stays on its owner's property; there is no county-wide requirement that any pet be sterilized. Sterilization only becomes mandatory as a court-imposed sanction, and only in narrow circumstances: Section 12(c) lets the Boulder County Sheriff's Office Animal Control Section or the District Attorney recommend a special sanction to the District Court after a conviction for a violation involving bodily injury to a person, or against a habitual offender. Among the sanctions a judge may order under Section 12(c)(2), alongside a secure enclosure, obedience training, a short two-foot leash and muzzle requirement, community service, or euthanasia, is to spay or neuter the dog.

The Animal Control Section must then conduct follow-up visits to confirm compliance and report back to the court. Ordinary bodily-injury violations are Class 2 Misdemeanors punishable by up to a $750 fine and 120 days in jail per offense under Section 12(b)(2), separate from any sterilization sanction the court adds.