Didn't Sugarfoot start out as Tenderfoot or is my senile mind playing tricks on me ?
The only one other than Bonanza above I can remember (I'm sure I'd know them if I heard them though) is Champion the Wonder Horse (now I've typed that I can remember Mr. Ed as well) although that doesn't strictly meet the criteria, but it is bit horsey.
I'm looking forward to hearing some old forgotten favourites again.
Cheers,br. Gary