Initial tank-encounters during the German invasion of the Soviet Union in 1941 virtually wiped out the pre-war armoured inventory of the USSR tanks of the BT series, the T28 and T35.
Soviet Army anti-tank dogs were kept hungry and trained to crawl under tanks to get their food.
In the combat area, they were fitted with a special fabric harness which contained 10-12 kg of high explosive in four pouches. On top of the harness was a spring-loaded trigger pin. When the dog crawled under a tank the trigger pin was depressed setting off a detonator and exploding the charge.
“Russian Combat Methods in World War II”, one of the historical studies in the German Report Series, prepared by the Historical Division, SSUSA, refers briefly to the antitank dogs:
“News of this insidious improvisation caused some alarm in the German panzer units and made them fire at all approaching dogs on sight. So far there is no evidence of any case where a German tank was destroyed by a mine dog. On the other hand, it was reported that several mine dogs fleeing from the fire of German tanks sought protection underneath Russian tanks which promptly blew up.”
Via warwriting for the full fascinating story.