Darrell Rooney Director Scott Wolf Scamp Voice Alyssa Milano Angel Voice Chazz Palminteri Buster Voice Jeff Bennett Tramp , Jock the Scottish Terrier , Trusty , Dogcatcher Voice Jodi Benson Lady Voice Bill Fagerbakke Mooch Voice Mickey Rooney Sparky Voice Bronson Pinchot Francois Voice Cathy Moriarty Ruby Voice Mary Kay Bergman Si Voice Debi Derryberry Annette Voice Barbara Goodson Darling Voice Nick Jameson Jim Dear Voice Tress MacNeille Aunt Sarah , Am Voice Andrew McDonough Junior Voice Rob Paulsen Otis Voice Kath Soucie Collette , Danielle Voice Frank Welker Reggie Voice April Winchell Mrs. Mahoney, the Street-Wig Woman Voice Jim Cummings Tony Voice Michael Gough Joe Actor Roger Bart Scamp Voice Jess Harnell Buster - the Chief Junkyard Dog Voice Melissa Manchester Voice Susan Egan Angel Voice Amick Byram Chorus Voice Susan Holder Chorus Voice Norman Large Chorus Voice Rick Logan Chorus Voice Bobbi Page Chorus Voice Jeannine Roussel Producer Bill Motz Writer Bob Roth Writer Tom Rogers Writer Flip Kobler Writer Cindy Marcus Writer Robert St. Pierre Production Design Robert Schaefer Art Director