To be a furry is to be counter to human nature. Other animals, according to human nature, are either dangerous, cute, or food. To appreciate them as equals, or to desire to be one, is just not something a typical human can comprehend, so the fall-back of sheepshagger is all they can understand, and that's when it falls apart.

I've learned to just not bother explaining it and list being furry the same as soemone would state they collect stamps.