War Dog

Some dogs are trained to silently locate booby traps and concealed enemies such as snipers. The dog's keen senses of smell and hearing would make them far more effective at detecting these dangers than humans. The best scout dogs are described as having a disposition intermediate to docile tracking dogs and aggressive attack dogs.
Scout dogs were used in World War II, Korea, and Vietnam by the United States to detect ambushes, weapon caches, or enemy fighters hiding underwater, with only reed breathing straws showing above the waterline. The US operated a number of scout dog platoons (assigned on a handler-and-dog team basis to individual patrols) and had a dedicated dog training school in Fort Benning, Georgia.
• Sentries
One of the earliest military-related uses, sentry dogs were used to defend camps or other priority areas at night and sometimes during the day. They would bark or growl to alert guards of a stranger's presence. During the Cold War, the American military used sentry dog teams outside of nuclear weapons storage areas. A test program was conducted in Vietnam to test sentry dogs, launched two days after a successful Vietcong attack on Da Nang Air Base (July 1, 1965). Forty dog teams were deployed to Vietnam for a four month test period, with teams placed on the perimeter in front of machine gun towers/bunkers. The detection of intruders resulted in a rapid deployment of reinforcements. The test was successful, so the handlers returned to the US while the dogs were reassigned to new handlers. The Air Force immediately started to ship dog teams to all the bases in Vietnam and Thailand.