Wash. Rev. Code § 18.92.010
Any person shall be regarded as practicing veterinary medicine, surgery and dentistry within the meaning of this chapter who shall, within this state, (1) by advertisement, or by any notice, sign, or other indication, or by a statement written, printed or oral, in public or private, made, done, or procured by himself or herself, or any other, at his or her request, for him or her, represent, claim, announce, make known or pretend his or her ability or willingness to diagnose or prognose or treat diseases, deformities, defects, wounds, or injuries of animals; (2) or who shall so advertise, make known, represent or claim his or her ability and willingness to prescribe or administer any drug, medicine, treatment, method or practice, or to perform any operation, manipulation, or apply any apparatus or appliance for cure, amelioration, correction or reduction or modification of any animal disease, deformity, defect, wound or injury, for hire, fee, compensation, or reward, promised, offered, expected, received, or accepted directly or indirectly; (3) or who shall within this state diagnose or prognose any animal diseases, deformities, defects, wounds or injuries, for hire, fee, reward, or compensation promised, offered, expected, received, or accepted directly or indirectly; (4) or who shall within this state prescribe or administer any drug, medicine, treatment, method or practice, or perform any operation, or manipulation, or apply any apparatus or appliance for the cure, amelioration, alleviation, correction, or modification of any animal disease, deformity, defect, wound, or injury, for hire, fee, compensation, or reward, promised, offered, expected, received or accepted directly or indirectly; (5) or who performs any manual procedure for the diagnosis of pregnancy, sterility, or infertility upon livestock; (6) or who implants any electronic device for the purpose of establishing or maintaining positive identification of animals.
The opening of an office or place of business for the practice of veterinary medicine, the use of a sign, card, device or advertisement as a practitioner of veterinary medicine or as a person skilled in such practice shall be prima facie evidence of engaging in the practice of veterinary medicine, surgery and dentistry.
RCW 18.92.010