Agents and Methods of Euthanasia by Species

Species Acceptable Conditionally acceptable
Amphibians Barbiturates, inhalant anesthetics (in appropriate species), CO, CO2,  Tricaine methane sulfonate, benzocaine hydrochloride, double pithing Penetrating captive bolt, gunshot, stunning and decapitation, decapitation and pithing
Birds  anesthetics, CO2, CO, gunshot (free ranging only) N2, Ar, cervical dislocation, decapitation, thoracic compression (small, free-ranging only)
Cats Barbiturates, inhalant anesthetics, CO, CO2, potassium chloride in conjunction with general anesthesia N2, Ar
Dogs Barbiturates, inhalant anesthetics, CO,  potassium chloride in conjunction with general anesthesia N2, Ar,  penetrating captive bolt, electrocution
Fish Barbiturates, inhalant anesthetics, CO2, Tricaine methane sulfonate, benzocaine hydrochloride, 2-phenoxyethanol Decapitation and pithing, Stunning and decapitation/pithing 
Horses Barbiturates, potassium chloride in conjunction with general anesthesia, penetrating captive bolt Chloral hydrate (IV, after sedation), gunshot, electrocution
Marine mammals Barbiturates, etorphine hydrochloride Gunshot
Mink, fox and other animals produced for fur Barbiturates, Inhalant anesthetics, CO, CO2 (mink require high concentrations for euthanasia without supplemental agents), Potassium chloride in conjunction with general anesthesia N2, Ar, electrocution, followed by cervical dislocation
Non-human primates Barbiturates Inhalant anesthetics, CO, CO2, N2, Ar
Rabbits Barbiturates, Inhalant anesthetics, CO, CO2, Potassium chloride in conjunction with general anesthesia N2, Ar, cervical dislocation  (<1 kg), decapitation, penetrating captive bolt
Reptiles Barbiturates, Inhalant anesthetics (in appropriate species), CO2 (in appropriate species) Penetrating captive bolt, Gunshot,  stunning and decapitation, decapitation and pithing
Rodents and other small animals Barbiturates, Inhalant anesthetics, CO, CO2,  microwave irradiation, Potassium chloride in conjunction with general anesthesia N2, Ar, cervical dislocation (rats <200 g), decapitation
Ruminants Barbiturates, Potassium chloride in conjunction with general anesthesia, penetrating captive bolt Chloral hydrate (IV, after sedation), gunshot, electrocution
Swine Barbiturates,CO2, Potassium chloride in conjunction with general anesthesia, Penetrating captive bolt  Inhalant anesthetics, CO, Chloral hydrate (IV, after sedation), gunshot, electrocution, blow to the head (<3 weeks of age)
Zoo Animals Barbiturates, Inhalant anesthetics, CO2, CO, Potassium chloride in conjunction with general anesthesia N2, Ar, Penetrating captive bolt, Gunshot
Free ranging wildlife Barbiturates IV or IP, Inhalant anesthetics, Potassium chloride in conjunction with general anesthesia CO2, CO, N2, Ar, Penetrating captive bolt, gunshot, kill traps

From 2000 Report of the AVMA Panel on Euthanasia.