Patent ID: 7549397

Claim:
A method of euthanizing one or more animals comprising the steps of: placing the one or more animals into a holding cage, wherein the holding cage includes a cover, at least an inlet, and at least one exhaust outlet, wherein the holding cage is connected to one or more gas sources for holding gas by way of one or more flow meters, wherein the one or more flow meters are connected in parallel to the one or more gas sources by way of one or more manifolds and one or more solenoids, and the one or more flow meters introduce gas from the one or more gas sources into the holding cage at a first flow rate for a first predetermined flow period of time and at a second flow rate for a second predetermined flow period of time such that the first predetermined flow period of time and the second predetermined flow period of time do not occur simultaneously; introducing a gas into the holding cage at the first flow rate until a narcotic set point for the one or more animals is achieved; ceasing introduction of the gas into the holding cage for a first wait period to ensure narcotic effects of the gas overtake the one or more animals; introducing the gas into the holding cage at the second flow rate until the gas accounts for approximately 100% of an internal atmosphere inside the holding cage; ceasing introduction of the gas into the holding cage for a second wait period to ensure irreversible euthanasia of the one or more animals; and removing and disposing of carcasses of the one or more animal.