Gas attack on the West Front, near St. Quentin 1918 -- a German messenger dog loosed by his handler. Dogs were used throughout the war as sentries, scouts, rescuers, messengers, and more. (Brett Butterworth) - image credit.
The first world war was only two months old, one hundred years ago, a maelstrom gorging on everything living and alive.
Vintage everyday has a fascinating series of black and white pictures showing humans and animals in World War I.
See also 28 July 1914 - Outbreak of World War I.