Small animal anesthetization gas mask with integrated valve function

An anesthetization gas mask for a small animal, comprising:

• a first mask part providing an inlet for an anesthetization gas;
• a second mask part for transmitting the anesthetization gas being mechanically connected to the first mask part;
• wherein the first and the second mask part at least partially define an anesthetization volume for receiving a mouth part of the small animal;
• wherein the second mask part for transmitting the anesthetization gas is movably connected to the first mask part, the first mask part manually movable by a user back and forth relative to the second mask part between a working position and a blocking position;
• wherein the first mask part and the second mask part cooperatively form a valve, the valve configured to either block or transmit the anesthetization gas flowing in either direction between the inlet and the anesthetization volume depending on whether the first mask part and the second mask part are in the working position or the blocking position;
• and wherein the anesthetization gas mask is geometrically constructed and configured wherein a movement operated manually of the first mask part by the user from the working position to the blocking position relative to the second mask part blocks the passage of anesthetization gas through the valve into the anesthetization volume.