During the First World War thousands of dogs were trained to perform duties such as delivering messages to the front, carrying equipment, and assisting with the wounded. They were exposed to many of the same dangers as the men on the front line. With the introduction of gas warfare, both sides of the conflict developed masks to protect dogs.
This example was used by a German messenger dog before it was captured by the 41st Battalion on 25 August 1918 near the town of Bray. Like many dog gas masks, it is designed to protect the eyes and ears, and prevent inhalation of gas. It has no canister for filtering the air, and worked by impregnating potassium carbonate and hexamine into the fabric.