No vendor permitted on the grounds of an association shall sell or deliver any horse feed, feed supplement, tonic, veterinary preparation, medication, veterinary equipment or supplies, or any substance containing any prohibited drug, unless he shall have filed with the official veterinarian a list of such items he intends to sell or deliver and has received the approval of the official veterinarian. Any vendor permitted regular access to the stable area shall obtain a license from the Board. The official veterinarian may restrict the sale of, prohibit the sale or delivery of, or place conditions on the sale or delivery of any item subject to approval.
Cal. Code Regs. Tit. 4, § 1861