Before working on the show, the dog "Happy" was a stray that was abused by her former male owner. Even though she was later rescued "Happy" still has a fear of men. Before the taping of every new season Stephen Collins, Barry Watson, and other adult male actors on the show have to spend some time with Happy for her to get used to them being around when doing scenes together.
At the start of the series' 10th season this became the longest running family drama on television beating out Little House on the Prairie (1974) and The Waltons (1972), both of which aired for nine seasons.
Series creator Brenda Hampton discovered "Happy" the dog on another set and then decided to write her into the show. She was only 7 months old when she did the pilot.
Barry Watson (Matt Camden) is the only series regular to have ever written (7.8 "Peer Pressure") and also direct an episode (9.16 "Brother Love") of the series.
During the fourth and fifth season of the series there was much controversy over co-star Jessica Biel's (Mary Camden) unhappiness over the show and her character Mary. She attempted to leave the show by getting fired when she posed for Gear Magazine to upset producers and network executives to let her out of her contract - which she'd later regret, as she admitted in later interviews and was now contented with the series.