It is unprofessional conduct for a licensee to prescribe, dispense, deliver, or order delivered any controlled substance, unless he is currently registered with the federal Drug Enforcement Administration (DEA) and the Texas Department of Public Safety (DPS) to dispense controlled substances. The requirement for DEA registration is waived for a DEA unregistered veterinarian employed by a DEA registered veterinarian, if the registrant has knowledge the employee is dispensing and/or administering controlled substances in the usual course of his employment. The employer must also give written permission for the employee to dispense/administer under the registrant's license and assure that the employee is currently registered with DPS and holds a current DPS controlled substances certificate. The DEA unregistered veterinarian employee may dispense and administer controlled substances, but in no instance may he procure, purchase, or prescribe a controlled substance (Code of Federal Regulations 21, Part 1300, paragraph 1301.24, and the Texas Controlled Substances Act).