Sandy was only a puppy when Punky Brewster (1984) premiered. He was continually trained throughout the show's run based on what the script called for him to do. He learned to ride a skateboard within the course of only a few days.
Sandy originally played the part of Brandon on Punky Brewster (1984) with his brother, Brandy. When the two dogs began to look different as they grew older, trainer Glen Garner requested that just one dog play Brandon from then on. Sandy was chosen because he aimed to please more than Brandy did, even though Brandy was seen as more intelligent and physically capable.
After Sandy's acting career had ceased, he was adopted by a family. One of the children in that family wound up being a cameraman for TMZ. It was him who broke the news to Soleil Moon Frye that Sandy had passed away. (He did not reveal when he passed.).