It is impossible to appeal the humanity of someone who does not already possess at least a little bit.
I know. Farmers and others who deal with animals and livestock for their living have all the opportunity to be cruel, but many of them, being Christian, understand that even though man has dominion over animals (similar to God’s dominion over us) that doesn’t equate to a license to be cruel.
There is, and should be respect for life and suffering in decent, moral people.