PDFWAC 246-945-505
Humane societies and animal control agencies—Approved legend drugs and approved controlled substances.
(1) The following legend drugs are designated as "approved legend drugs" for use by registered humane societies and animal control agencies for pre-euthanasia sedation:
(a) Acetylpromazine;
(b) Dexmedetomidine;
(c) Medetomidine; and
(d) Xylazine.
(2) Registered humane societies and animal control agencies may only use sodium pentobarbital to euthanize injured, sick, homeless or unwanted domestic pets, and domestic or wild animals.
(3) Any approved drug used by the registered humane society and animal control agency shall be marked "for veterinary use only."
(4) Staff of registered humane societies and animal control agencies may administer legend drugs and controlled substances which have been prescribed by a licensed veterinarian for a specific animal, which have been dispensed by a pharmacy or a veterinarian and are properly labeled in accordance with either RCW 18.64.246 or 69.41.050 and WAC 246-945-015 through 246-945-017.