Horse sizes can be changed by mods via a form at the Vet Office.
Horses can only have their size changed once in their lifetime.
Horse sizing follows breed-specific guidelines.
Warmblood: 15-17.3 hh
Thoroughbred: 15-17.3 hh
American Quarter Horse: 14-16.3 hh
Mustang: 14-15.3 hh
Sport Pony: 13-14.2 hh
PRE: 15-18hh
Friesian: 15-17.3 hh
Arabian: 14-16.3 hh
Fjord: 13-15.3 hh
Cob: 14-16.3 hh
Shire: 16-19.1 hh
Marwari: 14-16.3 hh
Mule: 12-17.3 hh
Donkey: 12-14.3 hh
(0.7) Can't Compete, Shouldn't be ridden
(0.8) Can't Compete, Shouldn't be ridden
(0.9) Can Compete
(1) Default, No Resize
(1.1) Can Compete
(1.2) Can Compete
(1.3) Can Compete
(1.4) Leisure,Driving/Pulling - Can't Compete