The licensing regulations of this chapter shall not be applicable to the following owners who use animals for diagnostic purposes or research, the use having been approved by the Board of Public Health of the State pursuant to the provisions of Section 1666 of the Health and Safety Code of the State; owners who use animals for teaching purposes in recognized educational institutions; owners of establishments which treat or board animals and which are owned or operated by veterinarians licensed by the State; and owners of pet shops, circuses, animal exhibits, and other enterprises maintaining animals which have been granted business licenses by the County. (§ 2, Ord. 703, eff. May 22, 1974)