When using CO2 for euthanasia, what should be maintained after apparent death?

When utilizing CO2 as a method for euthanasia, maintaining gas flow after apparent death is critical to ensure that the animal has experienced a complete and humane process. Continuing the flow for at least one minute allows for confirmation that the animal is indeed deceased and helps ensure that any residual gas in the chamber facilitates a complete loss of consciousness, which is paramount in order to adhere to humane guidelines for euthanasia.

This practice is supported by guidelines to minimize the potential for any distress or suffering that may occur if the gas flow is stopped too soon. Ensuring that the gas continues to flow for an appropriate duration allows for the physiological processes to conclude in a manner that aligns with ethical standards in animal care and welfare. This thorough approach reflects current best practices recognized in the field of veterinary medicine and animal research.

The other choices, while aiming for animal welfare, do not align with the established guidelines for CO2 euthanasia and miss the importance of ensuring complete cessation of brain function and confirming death through adequate gas exposure.