The Humane Society of the United States recommends euthanasia by injection whenver possible.  This method, when properly performed, has been found to be the most humane, safest, least stressful, and most professional choice. When euthanasia by injection is not possible due to legal constraints, carbon monoxide euthanasia may be a conditionally acceptable form of euthanasia.

These policies and guidelines are provided by The Humane Society of the United States to shelter and rescue organizations that practice or are evaluating the practice of carbon monoxide euthanasia.

For additional information on transitioning from carbon monoxide euthanasia, please contact our shelter services experts.

• The HSUS Statement on Euthanasia Methods for Animals in Shelters
• State laws regarding carbon monoxide euthanasia 
• View excerpts from and purchase The HSUS Euthanasia Training Manual

• Carbon Monoxide Euthanasia Cost Analysis Worksheet
• Euthanasia by Injection Cost Analysis Worksheet

• Animal Sheltering magazine examines how and why shelters are moving away from carbon monoxide euthanasia
• Virginia shelters phase out carbon monoxide euthanasia
• Euthanasia by injection training opportunities