(a) Only sodium pentobarbital may be used to euthanize a dog or cat in the custody of an animal shelter.
(b) When sodium pentobarbital is used to euthanize a dog or cat, the following requirements apply.
  (1) The preferential route of administration of sodium pentobarbital is intravenous injection by hypodermic needle. Other routes considered to be acceptable are:
    (A) intraperitoneal injection by hypodermic needle; or
    (B) intra-organ, limited to intraosseous, intracardiac, intrahepatic, intrasplenic, and intrarenal, injection by hypodermic needle.
  (2) Any injection must be administered using a new, undamaged sterilized hypodermic needle of a size suitable for the size and species of the animal.
  (3) Injection shall be conducted in an area out of public view and out of the view of another animal, except when euthanizing unweaned/nursing animals with their mother; when euthanizing a mother animal with her offspring, the mother animal shall be euthanized first immediately followed by euthanasia of her offspring. Additionally, the carcass(es) of any animal(s) shall be removed from the euthanasia area prior to a live animal(s) entering that area.
  (4) The area used for injection shall be in a quiet location and have sufficient lighting to allow for visual accuracy during the injection process.
  (5) A dose of sodium pentobarbital appropriate for the animal's weight shall be administered to that animal through the route most appropriate for that animal.
  (6) Each animal given sodium pentobarbital by intraperitoneal injection must be given 3 to 4 times the intravenous dose.
  (7) Each animal given sodium pentobarbital by intraperitoneal injection shall be placed in a quiet, darkened area and, except when euthanizing unweaned/nursing animals with their mother, separated from physical contact with any other animal(s) during the dying process. When euthanizing a mother animal with her offspring, the mother animal shall be euthanized first immediately followed by euthanasia of her offspring.
  (8) Intra-organ injection shall not be used unless the animal is unconscious or anesthetized so that the animal is unable to feel pain.
  (9) The carcass of any animal(s) euthanized by sodium pentobarbital must be stored and disposed of in a manner that minimizes the potential for scavenging by animals or humans.
(c) Any animal other than a dog or cat, including birds and reptiles, in the custody of an animal shelter shall be humanely euthanized only in accordance with the methods, recommendations, and procedures of the American Veterinary Medical Association (AVMA) in the latest edition of the AVMA Guidelines for the Euthanasia of Animals applicable to that species of animal.
(d) When commercially compressed carbon monoxide gas is used to euthanize an animal(s), the following requirements apply.
  (1) It must be performed in a commercially manufactured carbon monoxide chamber or one designed and constructed, at a minimum, to equal the effectiveness of a commercially manufactured chamber.
  (2) The chamber must be located outdoors or in a well-ventilated room.
  (3) The chamber must be airtight and equipped with the following:
    (A) an exhaust fan for indoor chambers which is capable of evacuating all gas from the chamber prior to the chamber being opened and is connected by a gas-type duct to the outdoors;
    (B) a gas flow regulator and flow meter for the canister;
    (C) a gas concentration gauge;
    (D) an accurate temperature gauge for monitoring the interior of the chamber;
    (E) if located indoors, a carbon monoxide monitor on the exterior of the chamber that is connected to an audible alarm system, which will sound in the room containing the chamber;
    (F) explosion-proof electrical equipment if equipment is exposed to carbon monoxide;
    (G) a view-port with either internal lighting or external lighting sufficient to allow visual surveillance of any animal(s) within the chamber; and
    (H) if designed to euthanize more than one animal at a time, independent sections or cages to separate individual animals.
  (4) The gas concentration process must achieve at least a 6% carbon monoxide gas concentration not to exceed 10% due to flammability and explosiveness throughout the chamber within 5 minutes after the introduction of carbon monoxide into the chamber is initiated.
  (5) The ambient temperature inside the chamber should not exceed 85 degrees Fahrenheit (29.4 degrees Celsius) when it contains a live animal(s). For an outdoor chamber, achievement may be facilitated by use of the chamber during early morning.
  (6) All equipment, as specified in paragraph (3)(A) - (H) of this subsection, must be in proper working order and used at all times during the operation of the chamber.
  (7) An animal(s) must be left in the chamber with a continuous gas supply for a minimum of 15 minutes.
  (8) The chamber must be thoroughly vented prior to removing any carcasses.
  (9) The chamber must be thoroughly cleaned after the completion of each cycle. Chamber surfaces must be constructed and maintained so they are impervious to moisture and can be readily sanitized.
  (10) Operation, maintenance, and safety instructions and guidelines must be displayed prominently in the area containing the chamber.
  (11) Carbon monoxide shall not be used to euthanize any animal reasonably presumed to be less than 16 weeks of age. Carbon monoxide shall also not be used to euthanize any animal that could be anticipated to have decreased respiratory function, such as the elderly, sick, injured, or pregnant. Such animals may be resistant to the effects of carbon monoxide and the time required to achieve death in these animals may be significantly increased. In animals with decreased respiratory function, carbon monoxide levels rise slowly, making it more likely that these animals will experience elevated levels of stress.
  (12) Only compatible animals of the same species may be placed in the chamber simultaneously.
  (13) No live animal(s) may be placed in the chamber with a dead animal(s).
(e) Prior to using any method of euthanasia, all available measures should be taken to minimize the fear, anxiety, and distress of the animal scheduled for euthanasia.
(f) When using any of the allowable methods of euthanasia, each animal must be monitored between the time euthanasia procedures have commenced and the time death occurs, and the animal's body must not be disposed of until death is confirmed by examination of the animal for cessation of vital signs.
(g) As specified under the Texas Health and Safety Code, §821.055, a person (excluding licensed veterinarians) may not euthanize any animal in the custody of an animal shelter unless the person has successfully completed a training course in the proper methods and techniques for euthanizing animals not later than three years before the date the person euthanizes the animal. The training course must be pre-approved by the department. A person has until the 120th day following the date of initial employment to complete this training.

Source Note: The provisions of this §169.84 adopted to be effective July 12, 2009, 34 TexReg 4527; amended to be effective December 1, 2013, 38 TexReg 8246