Colo. Rev. Stat. § 25-4-610
It is unlawful for any owner of any dog, cat, other pet animal, or other mammal which has not been inoculated as required by the order of the county board of health or board of health of a health department to allow it to run at large. The health department or health officer may capture and impound any such dog, cat, other pet animal, or other mammal found running at large and dispose of such animal in accordance with local program policy. Such power to impound and dispose shall extend to any and all animals unclaimed and found or suspected to be affected by rabies, whether wild or domestic. The division of parks and wildlife shall cooperate with and aid the health department or health officer in the enforcement of this section as it affects animals found or suspected to be affected by rabies when such animals are in its care, jurisdiction, or control.
C.R.S. § 25-4-610