If I were to be gifted a horse nowadays, I would've been angry. I would have to spend a lot of money in its food, in a blacksmith for horseshoes, grooming, cleaning his box, the rent of his box, extra taxes (depending on the government), veterinarian. So much money a simply horse would've cost me. And on top of that, imagine if the horse is sick and will just require surgery after surgery, draining my pockets even further. And I can't even sell him, he's pretty much a zombie horse.
Wait. But if I have those issues now, that raises the following question:
Between the start of the middle ages, until the Industrial revolution (Which majorly changed the revenue a horse could reek), what was on average the burden of owning an horse (Cost vs Income)?
Secondly, what would've happened if the cost of maintaining an horse was too high, but the horse would still be necessary as a ways to make a living? (They need him for transport / labor. When eating it just isn't viable)