If the canes were used as punishment, it wouldn't be considered child abuse. But if the beatings were profusive and weren't used solely as punishment but also as an expression of hatred, it would be considered as child abuse. I, for one, was whacked by a belt for doing something wrong as a child; in a matter of fact, a majority of parents use some sort of physical harm on their children for punishment. It is when the beatings become severe and overused for the wrong reasons that child abuse is taking place.
It's unfortunate, though, how parents could hurt their children like that with no feeling of remorse.