When there should be, but aren't, it tells us something.
Jeffrey Zaslow observed that we have words that describe the natural order of things, but not the aberrations that disturb that order. So, in the normal course of life, when death comes upon a family, those who live on become widows, widowers or orphans.
However, he noted, there is no word for one who has lost a child.
Similarly, while abnormal is the absence of normal, no word readily comes to mind as the opposite of abuse, especially when it's used in the context of children.
To be abnormal is not to be normal, to be absent is not to be present, but what is it not to abuse?
Good parenting - or good caregiving - is not defined by the absence of abuse.