After Pearl Harbor, the US military asked pet owners to donate their pet dogs to the war effort. The name of this program was Dogs for Defense. The dogs were trained and used for guard and patrol duties. To encourage the donation, they also advertised a program where the dogs would be deprogrammed after the war.
History
Prior to World War II, the US military did not have a formal K-9 corp and owned fewer than a hundred dogs (mostly sled dogs sled dogs in Alaska). After Pearl Harbor, a woman named Alene Erlanger pushed for the US military to begin using dogs.
References
Dogs For Defense Wikipedia(Text) CC BY-SA