Groaning is the most common vocalization that is associated with pain, discomfort, or stress. Without a doubt, if a horse is moaning and groaning, then something is wrong with him. This can be due to the rider’s weight, poor fit of the saddle, or even a medical condition.
The first thing to do is to make sure the horse is not in pain. If he is in pain, then you should not put any pressure on his body or ride him until he feels better. A good place to start is by checking his legs and feet for any wounds, cuts, or other injuries. If you find anything, make sure that you treat it immediately.
If you are not sure whether the horse is in pain, try to figure out what is bothering him and take measures to fix it.