Assistant Laboratory Animal Technician (ALAT) Practice Exam

Which source of CO2 is considered acceptable for euthanizing small mammals?

1. Liquid nitrogen

2. Compressed gas cylinder

3. Dry ice

4. Carbonated water

The correct answer is: Compressed gas cylinder

Using a compressed gas cylinder containing carbon dioxide (CO2) is considered an acceptable source for euthanizing small mammals due to its effectiveness and humane qualities. When properly administered, CO2 causes rapid unconsciousness followed by death, minimizing stress and pain for the animal. The method is widely accepted in veterinary practices and research facilities because it aligns with guidelines set by organizations such as the American Veterinary Medical Association. Other options like liquid nitrogen, dry ice, and carbonated water do not meet the standards for humane euthanasia. Liquid nitrogen can cause severe tissue damage and does not provide an acceptable method for euthanasia. Dry ice may induce distress to the animal before loss of consciousness occurs. Carbonated water contains CO2 but is not used in euthanasia practices due to insufficient concentration to induce the desired effect safely and reliably. The use of a compressed gas cylinder ensures a controlled and consistent delivery of CO2, making it the preferred choice in these scenarios.