A veterinarian licensed under this chapter may dispense veterinary legend drugs prescribed by other veterinarians licensed under this chapter, so long as, during any year, the total drugs so dispensed do not constitute more than five percent of the total dosage units of legend drugs the veterinarian dispenses and the veterinarian maintains records of his or her dispensing activities consistent with the requirements of chapters 18.64, 69.04, 69.41, and 69.50 RCW. For purposes of this section, a "veterinary legend drug" is a legend drug, as defined in chapter 69.41 RCW, which is either: (1) Restricted to use by licensed veterinarians by any law or regulation of the federal government, or (2) designated by rule by the pharmacy quality assurance commission as being a legend drug that one licensed veterinarian may dispense for another licensed veterinarian under this section.