The Return of Rusty.

A young Czechoslovak orphan, Loddy Bicek, befriended by an American army sergeant, is brought into the United States as a stowaway by the soldier. He is apprehended, but escapes and makes his way to the sergeant's home town. There, he is befriended by young Danny Mitchell and his dog, Rusty, a K-9 veteran of World War II. A third boy reports Loddy to the authorities, and when Loddy tries to run away, he falls into a deep ravine.