The Adventures of Rusty

The Adventures of Rusty is a 1945 drama film, the first in the Rusty series of childrens films. The series of eight films were made in the 1940s by Columbia Pictures with stories centered on Rusty a German shepherd dog. The film is notable for featuring the famous Ace the Wonder Dog as Rusty, the only appearance by Ace in the Rusty films.

A subplot involves two Nazi saboteurs Arno Frey and Eddie Parker who arrive in Lawtonville, attempting to evade the Coast Guard and blow up an installation. They ultimately try to take Rusty by speaking to him in German.The dog portraying Rusty would change frequently over the course of the series, with Flame having the most appearances as the character four. Dannys parents would also be portrayed by different actors in almost every installment. ........

Source: Wikipedia