Specifically, he became very useful at alerting soldiers to incoming gas attacks (after being caught in one himself and learning the smell). His advanced sense of smell allowed him to warn soldiers to get ready with gas masks.
His advanced hearing allowed Stubby to hear enemy soldiers heading towards his trenches, warning his soldiers silently so as not to make the enemy aware they were discovered.
Stubby also caught a German spy who tried to sneak into the trenches late at night, and raised the alarm so the spy could be captured and imprisoned.
The dog also learnt to differentiate between German and English, managing to search through the battlefields after the fight and find the wounded Allied soldiers (while ignoring the enemy soldiers). He would then bark to let medics and other soldiers know there was a friendly soldier to help - but if the soldier was too wounded, Stubby would stay and comfort them until they died.
He was pretty awesome, to be honest.
His advanced hearing allowed Stubby to hear enemy soldiers heading towards his trenches, warning his soldiers silently so as not to make the enemy aware they were discovered.
Stubby also caught a German spy who tried to sneak into the trenches late at night, and raised the alarm so the spy could be captured and imprisoned.
The dog also learnt to differentiate between German and English, managing to search through the battlefields after the fight and find the wounded Allied soldiers (while ignoring the enemy soldiers). He would then bark to let medics and other soldiers know there was a friendly soldier to help - but if the soldier was too wounded, Stubby would stay and comfort them until they died.
He was pretty awesome, to be honest.