Dogs were used by international forces to deliver vital messages. About a million dogs died in action. Dogs were often used to carry messages in battle. They would be turned loose to move silently to a second handler. This required a dog that was very loyal to two masters, otherwise the dog would not deliver the message on time, or at all. Some messenger dogs also performed other communication jobs, such as pulling telephone lines from one location to another. Sergeant Stubby, an American Pit Bull Terrier mix was the most decorated dog of WWI and became the first dog to be given a rank (of Sergeant) when he discovered, captured, and alerted the Allies to the presence of a German spy.