(1) The tax levied by RCW
82.08.020 does not apply to sales to farmers or to veterinarians of animal pharmaceuticals approved by the United States department of agriculture or by the United States food and drug administration, if the pharmaceutical is to be administered to an animal that is raised by a farmer for the purpose of producing for sale an agricultural product.
(2) The exemption is available only when the buyer provides the seller with an exemption certificate in a form and manner prescribed by the department. The seller must retain a copy of the certificate for the seller's files.
(3) For the purposes of this section and RCW
82.12.880, the following definitions apply:
(a) "Farmer" and "agricultural product" mean the same as in RCW
82.04.213.
(b) "Veterinarian" means a person who is licensed to practice veterinary medicine, surgery, or dentistry under chapter
18.92 RCW.