Maltreatment is what happens when a person (or animal) is abused or deliberately harmed. If you are concerned with the maltreatment of animals, circuses probably disturb you.
In the old days, some schoolchildren experienced maltreatment at the hands of their teachers, and while it happens less often today, many of them still deal with the maltreatment of playground bullies. Maltreatment of animals has been documented at large factory farms, and laws have been passed to protect them. Maltreatment adds the mal- prefix, meaning "badly," to treatment, "conduct toward someone."