To clarify what I mean with animal consciousness I mean whether or not it was believed animal were conscious beings with independent thought and feelings. I know that 17th century philosopher René Descartes claimed only humans had a 'non-physical mind', but I can't find anything about before then.
Furthermore with the treatment of animals I'm specifically wondering whether or not animal cruelty was truly looked down upon and punished or if it was just ignored. Additionally, was animal cruelty common in the era?
And finally, I know that in the Dutch language a horse actually shares human physical descriptions whereas other animals do not (i.e. 'hoofd' means head whereas 'kop' mean animal head). So this makes me wonder if horses were not only held in high regard but also seen as human like in terms of consciousness (perhaps differently than other animals?).
The treatment of horses was really quite... complicated in that particular time period, and there was a tremendous amount of writing and philosophy around it.
The late medieval treatment of horses was really quite terrible. Riders used cruel and painful bits, gigantic spurs with sharp points, and harsh training methods.
But, as the Renaissance came, people started reading and studying classical Greek texts, which they tried to apply to daily life. This happened with horses as well.
Primarily, they read Xenophon's "On Horsemanship." This stands as the philosophical and practical foundation of all modern horsemanship. He details things like grooming practices, the selection of a good horse, the training of horses, the care of the horse, and the necessity of humane and careful treatment of the horse.
Antoine de Pluvinel is often credited as the first of the classical French riding masters. While he learned from a rather cruel trainer, he advocated for the humane and ethical treatment of the animal, and believed that they should be trained in such a way that would elevate and improve upon the horse's natural tendencies.
With that in mind, there were many cruel riding masters. Federico Grisone, another master, once advised that, (paraphrase), "When the horse will not go forward, one should take a cat, tie the cat to a pole, and then hold the pole in such a way that the cat may bite and scratch the horse in the legs and the flank." His text, "The Rules of Horsemanship" detail his cruel methods first hand.
In any regard, horses were typically seen as something valuable, and, while not quite human, definitely special and able to be trained and educated in a way that they could be improved beyond any other animal. The training and breeding of horses was often considered one of the most gentlemanly and refined topics of conversation.
Sir Philip Sidney wrote this in his introduction to "The Defense of Posey":
Nay, to so unbelieved a point he proceeded, as that no earthly thing bred such wonder to a prince as to be a good horseman; skill of government was but a pedanteria in comparison. Then would he add certain praises, by telling what a peerless beast the horse was, the only serviceable courtier without flattery, the beast of most beauty, faithfulness, courage, and such more, that if I had not been a piece of a logician before I came to him, I think he would have persuaded me to have wished myself a horse.
(Emphasis mine).
Sidney is describing a riding lesson he had with a riding master. The riding master is singing the praises of the horse, and is expressing why the horse is such a valuable animal- to the point where being like a horse would almost be better than being a man.
Essentially, according to the riding master, the horse is the only employee one can have who does not think highly of himself, and who will work at any time, regardless of the circumstances, but will do so with all the good qualities of a good servant.