This chapter, except Section 14363, does not apply to any of the following:
(a)
Any livestock drug which is sold exclusively to, and used exclusively by, or under the direction of, a licensed veterinarian, nor to any livestock drug which is compounded by a registered pharmacist upon the prescription of a licensed veterinarian.
(b)
Any drug or other preparation which is dispensed or compounded by a registered pharmacist at the request of the purchaser if such drug or preparation is sold at retail.
(c)
Any commercial feed which is subject to Chapter 6 (commencing with Section 14901) of this division, irrespective of the presence in such commercial feed of any ingredients which otherwise would constitute a livestock drug.