No dogs of fierce, dangerous or vicious propensity and no female in heat shall be released from confinement, except upon approval of the animal control officer after payment of the fees provided for in this chapter; provided, however, that if any dangerous, fierce or vicious dog is found running at large and cannot be safely taken up and impounded, such dog may be slain by any law enforcement officer. (Ord. 787, 12-3-2007)