[Pausing to fondly remember FReeper Inge_Cav]
Another breed, not as flashy but with an important role are the Old Guard horses of Arlington National Cemetery.
If anyone is at Arlington, you can stop by their stables....the entrance is into Ft Meyers, near the back of Arlington. It's a bit fussy, these days, to get through the guard at the gate....but if you tell him you're there to see the stable....they'll let you through. The caregivers are so nice to talk with. If you have never seen a Full Honors Funeral ...it's a life-changing experience.
They have a very rigorous program to adopt a retiring caisson horse.
http://www.army.mil/info/organization/unitsandcommands/commandstructure/theoldguard/specplt/adoptahorse.htm