The deployment of animals in war is as old as war itself; but the concept of kicking dogs out of perfectly good airplanes so they will parachute onto snowy hilltops and deliver aid to wounded combatants strictly dates to World War II. This printable "Collier's Magazine" article tells the story of the "Parapups":
"Completely G.I., the dogs have service records, serial numbers, enlistment papers and shots against disease. Sentimentalists along the Alaska Division even proposed that they be authorized to wear Parawings after five jumps."
Click here to read about the use of dogs in W.W. I.