Edit
When a pet owner starts to abuse their pet yukkuri. In pet betrayal, the abuse is done neither for discipline or punishment. Rather, in this case the owner never actually intended to care for their pet in the first place and adopts their pet fully intending on abusing them.
These abusers adopt their victims as "pet yukkuri" to give them hopes of a pet life full of easiness with clothes and sweets, only to crush their hopes and laugh at their confusion on how their lives aren't as happy as they expected. Some even went as far as pretending to love their pet and forming a strong bond with them over a long time to maximize the psychological abuse they'll eventually receive once they're betrayed.
Tag can also be used in cases where an owner didn't plan on abusing their pet at first, but suddenly turned from a yu-lover into an abyuser for various reasons.
Nobody here but us chickens!