In my old Days book the last reference I can find to him is:
"He and his sister Marie fell in love, but the truth of his identity was discovered before they consumated their relationship." There is also something about his pet monkey recognizing him, but nothing about how or why he left.
He was on again later but not for long. Don’t remember what happened to him.
Wikipedia says he left for good in 1979 and returned briefly for Tom and Alice’s fifthieth wedding anniversary in March of 1980, and is presumably told of both his fathers Tom Sr’s death in 1994 and his brother Mickey’s death in 2010 but does not return to town for either of the funerals.
Sandy who was also a doctor and on the show fairly briefly. I was thinking that Tommy had gotten sick off the show and they had him pass away but that is just a hunch. There was also a point where "Tommy" didn’t want to be a Horton or went back to the life he had when he first returned.
I watched the last episode that John Lupton(Tom Jr) appeared on in 1979. I remember the actor well from the Broken Arrow tv series. I think Sandy Horton was his daughter and that carried on the name for a few years. Was Nick Fallon related to Sandy, I never could remember wher he fit in the family tree?