Question

Which of the following methods of euthanasia would not be acceptable in an adult rat over 200 grams in weight?

1) Intraperitoneal injection of pentobarbital
2) Intracardiac injection of potassium chloride
3) Decapitation
4) Carbon dioxide inhalation

Answer 1

Intracardiac injection of potassium chloride without anesthesia is not an acceptable euthanasia method for an adult rat over 200 grams. Potassium injection is lethal as it disrupts the heart's electrochemical gradient. Other methods such as decapitation, carbon dioxide inhalation, and pentobarbital injection are acceptable.

Step-by-step explanation:

Injecting a potassium solution into the blood is lethal because potassium disrupts the electrochemical gradient across cell membranes, particularly in cardiac muscle cells, preventing them from contracting effectively and leading to cardiac arrest. Decapitation and carbon dioxide inhalation are acceptable methods of euthanasia for small rodents, according to the American Veterinary Medical Association (AVMA) when performed by trained individuals and with appropriate equipment to minimize suffering. Intraperitoneal injection of pentobarbital is also an acceptable method when performed correctly.