The most acceptable method of humane euthanasia for dogs is an intravenous injection of sodium pentobarbital, instructs the American Veterinary Medical Association. The laws governing humane euthanasia vary from state to state.
In a veterinary setting, an alternate IV anesthetic such as propofol or the combination of ketamine and xylazine may be used when the IV injection of pentobarbital is unavailable, states the AVMA. If a dog is extremely ill and a vein is not easily found for an IV injection, some euthanasia solutions may be administered in the heart, bone marrow, spleen, liver or kidneys. Alternative routes may only be utilized if the dog is anesthetized previous to the administration of the euthanasia solution.
For dogs who weigh less than 7 kilograms, an overdose of inhaled anesthetic administered via gas chamber can be considered as a secondary option, notes the AVMA. Due to the side effects and the potential for recovery, this option is not ideal.
In certain situations, such as in a laboratory, in a shelter or in a setting governed by law enforcement officers, a licensed veterinarian may be unavailable to provide an acceptable solution or gas anesthetic for humane euthanasia, explains the AVMA. After all attempts to provide a preferred method have been exhausted, authorized individuals may resort to using alternative drugs, a gun, a penetrating captive bolt or electrocution.