CO HB1231

Prohibits routine tail docking of dairy cattle, defined as cutting or removing a portion of bone, nerve, muscle, or tendon of an animal's tail.

Permits tail docking only when performed by a licensed veterinarian for therapeutic purposes using anesthesia and suitable instruments under hygienic conditions in a manner that minimizes long-term pain and suffering.

Defines "therapeutic" as medically necessary treatment for sick or injured animals, excluding merely prophylactic treatments.

Violators commit a Class 2 petty offense with fines not to exceed $500; being part of existing animal husbandry practices is not a valid defense.

Establishes an affirmative defense for tail docking performed before December 1, 2015, with the act taking effect on that date pending voter approval if a referendum petition is filed within 90 days.