An animal anesthetization device facilitates anesthetization of an animal, or simultaneous anesthetization of a litter of animals, prior to a procedure such as tail docking, castration, or the like. The device includes a box having a bottom wall and a perimeter wall coupled to and extending upwardly from the bottom wall defining an interior space. A lid is coupled to the box wherein the interior space is selectively enclosed. A valve is coupled to the box. A canister has a dispensing nozzle which is selectively engageable to the valve wherein contents of the canister are dispensed into the interior space of the box. An anesthetizing agent is positioned in the canister and dispensed into the box to anesthetize one or more animals in the box.