Yes. Horses should always have a clean and dry place to stand, in general standing in a stall all day - even a dry clean one - is not good for the horses physical or mental heath.
But if you as the owner has no choice, then be sure to keep the stall clean and the bedding fresh.
Horse.
Play Let's Jump mini-game and find some puddles on the background. Jump into them and your horse will become muddy, than you can clean it.
a white horse sleeps by standing up
Never pull a horse's tail.
The horse is one animal that is capable of sleeping in a standing position.
If a horse is bored it will windsuck, start pawing the floor, and will chew wood.
No it can not, it just thinks it is another horse standing in front it, rather funny actually.
The basic harness item your horse should have is a breastplate or standing martingale
Talk to the person standing next to the horse. He or she will tell you if you can tame him, you can have him. You then get on the horse, and keep your mouse in the circle for a while. When the horse stops, you have earned the horse, and his trust.
Horse Behaviour
Hermes
There are several ways a horse can loose its hair. Either by a fungus such as rainrot, or something it got from a poininous plant and started scratching itself raw.