Dan is of course just a generic horse, in all probability--a very common name for a cowboy's horse.    But one of the most famous horses of the turn of the 20th century was Dan Patch--is there a link there--who knows?

By the way, thanks, Mr. Happy, for that link to Marty Robbins singing. He really was wonderful--one of the alltime best in C & W-- and it's such a joy to see and hear him singing some of the songs they have on YouTube.