According to the account of his heroism:
Tweed went on duty with a Scottish Canadian regiment at Amiens in 1918. The Germans broke through and cut off the British front line, and had they gone but a little further would probably have captured the town. Three dogs were sent to the headquarters of the French Colonial, 3 kilometers back, with the message: “Send up reinforcement and small round ammunition.” Tweed ran through the German barrage and arrived in ten minutes, and the French were sent up. They straightened out the lines and saved Amiens from the Germans. Tweed became so well known that units would request him, and he never faltered in his service.