Here are some notes on buying a horse for ornerie, from The Book Containing the Treatises of Hawking, Hunting, Coat-armour, Fishing, and Blasing of Arms.
A good horse sholde have xv proprytees and condycions.
That is to wyte, thre of a man, thre of a woman, thre of a foxe, thre of an hare: and thre of an asse.
Of a man: bolde: prowde: and hardy.
Of a woman: fayr brested: fayr of heere: & easy to lippe upon.
Of a foxe: a fayr taylle: shorte eeres wyth a good trotte.
Of an haare: a grete eye: a drye heed: and well rennynge.
Of an asse: a bygge chynn: a flatte legge: & a good hove.
Well travelyd wymen nor well travelid horse were never gode.