The_Gobo

You have a cat as property, yet cats love being there. In that case, who cares? You could say that a cat is a slave, by that logic. 

No one could not,

because:

1: a cat does no typically work.

2: a cat is not a human being/ reasonably sentient lifeform.

And as to the 'who cares' thing...

well, given then whole countries have gone to war over this very topic, I think it bears considering what a slave is and how the term should be used appropriately to prevent people from being used/abused in such a manner as you had originally assumed the term to be exclusive to.

The American civil war was not started by slavery, though it did feed the flames. A New Yorker wrote a "realistic fiction novel" called "Uncle Tom's Cabin" which sparked the hatred for slavery. In the end, the main character (a slave) was beaten to death by the slave owner (which was illegal). People assumed that all slaveowners treated their humans this way, as the author claimed she "did research"

No, if very few, slave owner treated their slaves this way. In fact, some led very lavish lives. Some were even paid quite handsomely by their captors, so if they worked hard enough, they could have freedom if they so chose to.

A cat does work to stay in your house and be fed. They love you unconditionally. If they didn't and hurt you, scratched you, tore up your things, left dead rats and hairballs everywhere, etc. you'd probably consider getting rid of it. Cat = slave