Depends on the type of horse and many more factors.
its depend on the stamina of the horse but horse can run a lot.
Sonic can run at 3000 kilometers per hour.
three
Many times a horse will run because it is scared.
10
88.5 kph
Terry Fox Ran 5,373 Kilometers
13.5km
2.782672678
9
20 kilometers.
If the horse is a Quarter Horse, it can run at over 50 mph. If it's anything else, it probably will run at about 40 mph. With barrels, however, the horse probably won't be able to reach full speed.