Pulling trailers is what those trucks were made for, 19K miles a year is like a leisurely Sunday afternoon walk, for a 5.9 cummins with a horse trailer behind it. They weren't built for getting grocery's and taking kids to little league games.
My 1999 3500 rolled 100k miles, it's first 11 months on planet earth, 95% of those miles were with a loaded 40' gooseneck behind it. It had 8 miles on it, when I cut the muffler off and straight pipped it, then I took a 4" hole saw to the bed floor to put a gooseneck hitch it, so I could go latch on to my new trailer, and go start hauling loads so that truck would pay for itself. It was less then 30 days old and it had 9800 miles on it.
Good times....