Many breeds were represented and often used for specialised roles. Two groups often overlooked by war historians were dogs used as ratters and as the YMCA Cigarette Dogs. 

Ratters helped clear the trenches of the ubiquitous rodents which plagued the trenches and small dogs – sponsored by the YMCA – also delivered cartons of cigarettes to troops on the front lines.

With their plucky nature and physical resilience, Jack Russells were often chosen for these roles. They also served as mascots, and as living hot-water bottles, keeping soldiers warm in intolerable conditions.

One Jack Russell, a mascot of English soldiers, was destined for a place in history.

The story goes in early 1915 the dog chased a rat across No Mans Land and jumped into the German trenches, landing at the feet of the young messenger, Adolf Hitler. Hitler kept the dog at his side for the next few years; he named him Fuchs (little fox) and taught him tricks.

In August 1917, a railway official offered Hitler 200 Marks for Fuchs, which was refused: "I can look at him like I look at a human being," Hitler had written about Fuchs. "I am crazy about him." The dog was stolen later that day.

It was said Hitler would have avoided the 1918 incident, which left him temporarily blinded by British gas attack in Flanders, had the small dog still been at his side to warn him.