Two German dispatch dog sit in a trench with fitted gas masks awaiting ‘instructions’ . The scene above was repeated hundreds of times over by canines throughout the Great War. Man’s ‘best friend’ serviced as messengers, often jumping back and forth over trenches, as sentries and as ambulance dogs trained to find wounded soldiers.
The use of dogs during wartime is not something new. In ancient times, amongst Greek and Roman armies dogs served also as sentries or patrols. They were sometimes even sent into battle strapped with armour and spiked collars to attack the enemy.
In our modern era, like the Romans, the Soviets starved dogs then unleashed them onto the battlefield. The Russians trained their dogs to seek out food from under tanks. During battle engagements they were strapped with anti tank bombs and, after being unleashed, they ran beneath tanks, with tragic results. Nowadays, in a world more ‘politically correct’ armed forces, in general, are a little more respectful of the canine.
Rearview Mirror 
Very interesting. It’s necessary to remember too. Regards.