I suppose it is a bit like cheating with a copy of Glenn Ohrlin's The Hell-Bound Train in hand, but here are a few from that treasure of cowboy lore.

I am going to include just those songs where the horse is the main character or has at least a top supporting role - horses with names or at least great stories to tell! I don't think I have listed any that have already been mentioned.

Windy Bill
Bonny Black Bess
Walking John
He Rode The Strawberry Roan (Yes, I think it might owe something to a song already mentioned)
Tipperary
Outlaw Dunny
Midnight
Starlight
The Bronco Buster
My Old Pinto Pal