They were often sent out after large battles, where they would seek out wounded soldiers, and they were well-suited to the conditions of trench warfare.
A typical mercy dog in World War I was outfitted with a saddlebag that had water, liquor, and first aid supplies.
[5][6]: 25–26 Some dogs were also involved in pulling soldiers on carts between the front lines and medical bases further back.
[5][8] A military surgeon praised the dog's abilities to triage wounded soldiers, saying "They sometimes lead us to the bodies we think have no life in them, but when we bring them back to the doctors [.
[10] A program to train mercy dogs in 1895 begun by Jean Bungartz in Germany was described as a "novel experiment".
[17] As a result of his advocacy, Britain created a British War Dog School with Richardson as the commander.
[22] During that war, the United States Army Medical Corps used ambulances with six casualty dogs, mainly Pointers and setters, to find wounded soldiers.
[25] The United States Army utilized a casualty dog program during the Korean War to find wounded soldiers.
[26] After World War II ended, the American Red Cross began a therapy dog program, which continued until at least 2019.
[5] A historical fiction book, Darling, Mercy Dog by Alison Hart, was published in 2013.
[27] The 2014 video game Valiant Hearts: The Great War features a German medical dog named Walt, who takes on a prominent story and gameplay role.