A wealthy industrialist wants to buy little Rex, but the Antonius family, who bred him, turn him down. So, without further ado, he has the puppy kidnapped. But Rex, of course, isn't stupid and manages to escape his kidnappers. With his last ounce of strength, he drags himself to Joe Felsner's farm and befriends his grandson, Benny.
| Actor | Role |
|---|---|
| RRaphael GhobadlooBenny Nachmann | Benny Nachmann |
 Friedrich von ThunJoe Felsner | Joe Felsner |
 Christine NeubauerChristine Nachmann | Christine Nachmann |
 Gertraud JessererElisabeth Schmied | Elisabeth Schmied |
 Wolfgang BöckRudolf Kainz | Rudolf Kainz |
| KKitty SpeiserEva Antonius | Eva Antonius |
 Vitus ZeplichalKurt Antonius | Kurt Antonius |
| MMarcus SiebertNot listed | Not listed |
 Heinz SchubertNot listed | Not listed |
 William MangNot listed | Not listed |
 Ida KrottendorfFrau Kramer | Frau Kramer |
 Thomas MorrisPospischil | Pospischil |
| MMartha DanglNot listed | Not listed |
| MManuel LöfflerNot listed | Not listed |
| MMichael Walde-BergerNot listed | Not listed |
| MMarie Christine GiulianiNot listed | Not listed |
 Andrea KieslingNachbarin (uncredited) | Nachbarin (uncredited) |