Anti-Tank Dogs - противотанковые собаки

The Anti-Tank Dogs were a Soviet military program where German Shepherds were trained to carry explosives to tanks and armoured vehicles. 40,000 dogs were intended to assist in curbing the German advance at the eastern front.

The first issues arose when the dogs wouldn't dive under the active enemy tanks as they'd only been trained on non-moving and non-shooting vehicles, so they would become scared return to their handlers... which could lead to explosive consequences!

Another serious issue was that the Soviets trained the dogs using their own diesel engine-powered tanks, however the German tanks used gasoline engines. Given dogs rely heavily on their keen sense of smell, they immediately sought out the familiar Soviet tanks, completely ignoring the strange-smelling German ones. As you can imagine, this wasn't particularly ideal for the longevity of the Soviet crews.

The program was started in 1930 and lasted until 1946 when, plagued by issues, it was unsurprisingly shut down.