The lieutenant who introduced ambulance dogs in Sweden in 1905

Dogs have since ancient times been used in warfare in different ways, e.g. as "war dogs" in combat, as scouts, sentries and trackers. The use of ambulance dogs, which were trained to locate wounded soldiers, was quite common e.g. in Germany in the early 20th century.
In Sweden, lieutenant E. B:son Lilliehöök was the first person to train ambulance dogs in 1905:

Lietenant E. B:son Lilliehöök together with two of his ambulance dogs in 1905.

In World War I ambulance dogs saved thousands of wounded soldiers:

Red Cross dogs – also known as mercy or ambulance dogs – played an important role in World War I, as they were trained to locate wounded soldiers and bring back help. Injured WWI troops were known to crawl into thickets and concealed areas, which made it difficult for medics to locate them. Owing to their excellent sense of smell and keen hearing, dogs were able to find these wounded soldiers and alert their masters. During the war, it was often only possible to carry wounded soldiers out at night, so Red Cross dogs proved especially effective. The Germans, Italians, French, Russians and British all used ambulance dogs during the Great War. In fact, in his book Scout, Red Cross and Army Dogs, American writer Theo Jager estimated that there were around 10,000 Red Cross dogs in use by the end of the war.