The provisions of this section shall not apply to dogs used by a law enforcement agency for police work, nor to dogs or cats in the custody of a veterinarian or animal shelter or animal rescuer, or whose owners are nonresidents temporarily within the city for a period not exceeding 30 days. (Ord. 1511 § 3, 1993; Ord. 1279 § 3, 1987; Ord. 1168 § 2, 1985).