Lassie - Season 16 - Eps 22: Chucka
Bob and his Navajo guide Sam find a dog swimming across Lake Powell on their way to survey tribal lands and rescue him; he is Chucka, an indolent dog who'd rather rest or play than tend sheep. But Chucka must ""grow up"" quickly after his shepherd owner, Charlie Ngani, is injured and Lassie must go for help.
About Lassie

Title: Lassie
First Air Date: 1954-09-12
Last Air Date: 1973-03-24
Status: Ended
Rating: 6.1/10 (from 65 votes)
Language: EN
Seasons: 20
Total Episodes: 591
Network: CBS
Genres: Action & Adventure, Drama, Family, Comedy
Production Companies: Unknown
Synopsis
Lassie is the pet of Jeff Miller, an 11-year-old farm boy. The two become best friends and enjoy family adventures in the American countryside, teaching each other about love, nature and commitment.
Cast

Hugh Reilly
Paul Martin

Josh Albee
Mike Bishop

Larry Pennell
Keith Holden

Larry Wilcox
Dale Mitchell