Guidelines for Euthanasia of Rodents Using Carbon Dioxide

Rodents must be euthanized by trained personnel using appropriate technique, equipment and agents. This is necessary to ensure a painless death that satisfies research requirements. Death should be induced as painlessly and quickly as possible. Upon completion of the procedure, death must be confirmed by an appropriate method, such as ascertaining cardiac and respiratory arrest or noting an animal's fixed and dilated pupils1. Whenever practical, euthanasia should not be performed in the animal room. The euthanasia method must be appropriate to the species and age of the animal, approved in the animal study proposal and must conform to the most recent AVMA Guidelines on Euthanasia2. CO2 inhalation is the most common method of euthanasia used at NIH for mice, rats, guinea pigs and hamsters. A few important aspects of this procedure are: 1. Neonatal animals (up to 10 days of age) are resistant to the effects of CO2. Please refer t