The Lost Media Wiki’s article on the subject! Cathy, Cathy's Last Resort and Cathy's Valentine are three animated specials that aired in 1987, 1988 and 1989 respectively, based on the comic strip Cathy by Cathy Guisewite and produced by Bill Melendez and Lee Mendelson, known for producing the Peanuts specials.
Although they received critical acclaim and the first special won Guisewite a Primetime Emmy for Outstanding Animated Program, these specials have never been rebroadcast since their first years, let alone released on VHS or DVD.
All three specials have been uploaded onto YouTube in various qualities. Youtube is the only site where the specials are available for viewing.