After Dolly, a retired milk-wagon horse refuses to eat while her owner is out of town; Opie becomes really worried that something is wrong with her. Unsure of what to do, Opie turns to Goober, Howard and Andy for help in getting the horse to eat. It is only after Mr. Simpson returns home from his vacation that he and Opie discover that Dolly refuses to eat because she misses going to work every day. (thetvdb.com)