Over 16 million animals served in the First World War. They were used for transport, communication and companionship.
In 1914, both sides had large cavalry forces. Horse and camel-mounted troops were used in the desert campaigns throughout the war, but on the Western Front, new weapons like the machine gun made cavalry charges increasingly difficult.
However, animals remained a crucial part of the war effort. Horses, donkeys, mules and camels carried food, water, ammunition and medical supplies to men at the front, and dogs and pigeons carried messages. Canaries were used to detect poisonous gas, and cats and dogs were trained to hunt rats in the trenches.
Animals were not only used for work. Dogs, cats, and more unusual animals including monkeys, bears and lions, were kept as pets and mascots to raise morale and provide comfort amidst the hardships of war.