The writer-director's father, Joey Bishop, is seen briefly and speaks one word---"Hello." His character runs Gottlieb's Mortuary, Gottlieb being Bishop's real name, i.e. Joseph Abraham Gottlieb. He played a character named "Mr. Gottlieb." This was his final film.
Film critic Roger Ebert hated this movie, testifying that it was "the first movie I have seen that does not improve on the sight of a blank screen viewed for the same length of time."
Mad Dogs (1996) is notable for the various cameo appearances, including the first - and final - film appearance by Christopher Jones in over a quarter-century, since Les troupes de la colère (1968).
Richard Pryor appears as Jimmy the Grave Digger. He is in only one scene, and speaks a few lines. He is shown in a wheelchair, and his voice is garbled. This would be Pryor's second-to-last film appearance.
Rob Reiner is a limo driver, explaining his humorous philosophy on life to Dreyfuss. Reiner and Larry Bishop were once professional comedy partners.