Sorry but all of you saying the guy with the cat is the idiot are wrong. Were I come from we call these kinds of dogs a nuisance and problematic. They most often end up being shot or taken to the vet to be euthanized. We do not tolerate dangerous dogs that kill things at random. My great uncle thought it was funny to train his hunting dogs using cats until they started tearing up all out cats and everyone else's cats in the neighborhood and they started disappearing. He started getting vet bills too from folks cats that had to be taken to the vet. One of my cousins lost four of his huskies due to their wandering killing habits Twice at diffrent two of his dogs decided it would be good idea to chase and kill our neighbors livestock our neighbore put them to sleep both times. One must be responsible about owning a dog and this kind of animal should never be kept. If It chased my kitten it would get hit hard and if it persisted in its stupidity and its owner would not do anything to curb its blood lust It would be put down. There is nothing cool about a dog killing things. If you think so then you need to get checked for mental illness.
Your roommate has every right to be just as happy as you and have a pet that they like. You are the problem and trouble maker here. You show a classic selfish, entitled attitude. Good dogs behave and get along with anything and everyone in their home and neighborhood. As do good humans. A good human goes out of their way to make sure that no harm comes to anything and does not make excuses or blame others for their failings or their pets. They put others first and themselves last. If I had a bad dog like yours it would be swiftly taught that this kind of attitude about things was unacceptable and if persisted in its killing ways it would be put to sleep. I do not tolerate dangerous, misbehaving animals of any kind. Dogs are a non native species in most areas and are pest species and thus they are not irreplaceable. Native wildlife on the other hand is a whole other matter and I will always defend it were non native, invasive species threaten or harass it in any way shape or form. The same goes for anyone else's animals that are being threatened by any dangerous "pet".
There is a rule and order to life that should be strictly adhered too to keep everyone and everything safe and happy. You my friend are outside the bounds of this rule and order and are the one that needs to get your act together and make sure your pest behaves in a polite sociable fashion to all things. If she attacks and kills things at random and will she at some point will attack you or your roommate. You show very clearly here that you are the trouble maker with your very ugly statements that ooze and drip with self and selfish attitude. It screams, "I, I, ME, ME!" Oh so very loudly. Get a grip you ain't all that nobody is. Owning your mistakes, taking responsibility for them, and not playing the blame game is how one shows themselves to be a true adult.
I have lived long enough to not give a crap about what folks think and come right to the point and give what needs to be given without pussy footing around to avoid hurting someone feelings. If they are hurt well than you should not have asked such a loaded question and it shows that you have not reached the realm of being a true adult.