Games : Is there any way to remove pet's ownership?

Previously I make all my animals has their owner except the cats. Now when I'm thinking of keeping only goat, sheep,dogs and kill others. I realize I can't cancel ownership.

After searching on Google, I found some ways:

1.Kill the pet with magma or trap etc... ,but will make dwarf unhappy

2.Kill the dwarf, but almost EVERY dwarf has pet, means I need to kill every dwarf.

So, is there anyway to turn the pet back to "no owner" condition? Like mod, dwarf therapist, DFhack, or change through the raw files ?