Canines are trained for a range of specialisms, including protection, ensuring bases and military sites are kept secure, to detecting arms and explosives.
The value of the dogs to the military remains clear - each year the Royal Army Veterinary Corps trains up to 170 dogs every year, which go on to serve in the military and police force.
Meanwhile, horses, once a key part of battlefield tactics, continue to play a large role in a ceremonial capacity.
Mules are used by the German Army to navigate mountains with equipment loads, while the US Marines' Mountain Warfare Centre uses "horses and mules as a way of transporting people, weapons and equipment across high altitude complex compartmentalised terrain".
Even eagles have been trained in some nations to hunt drones.