Definition: Given a real-life anecdote of a complex ethical situation, generate a suitable title that describes the main event/root cause of the situation. Imagine that the given text is a social media post, and you have to write the title of the post, so the users can decide to read the main text or not.
Input: I need some outside opinions on this. Throwaway because she knows my reddit handle. 

My fiancee, 22, and me, 21, have two cats. She grew up with always having dogs, so is experienced in raising and caring for dogs. She moved in with me a year ago and then we got both of our cats after that.  Both cats dumped on us. We have raised from the brink of death back to health. They absolutely adore us, but favor me over her when it comes to bedtime and couch vegging.

She recently expressed interest in adopting a dog. So she could have companionship when off work as she works 3 12 hour shifts a week. 
I of course said yes, so we started looking to adopt at the local shelter, we found a dog after a week of searching and the shelter said that she was great with other dogs and cats alike. 

We placed the application for adoption and were approved immediately, so we brought the dog home (chow chow mix) 

The first day we spent with a professional dog trainer helping us do introductions, the dog at first didn't care about the cats, but after 3 days she has started growling whenever she sees them, lunging snarling, etc. Basically If we didn't have the dog leashed she wouldve attacked and tried to kill the cats. 

We tried separating them into rooms but nothing has worked. I told her I dont want to see our cats torn to shreds if our super visions lapsed. We never leave the dog with the cats obviously, as she is crate trained. 

Just today the dog has lunged at one of our cats snarling and growling. 

I told her we cant keep the dog and need to bring it back to the shelter as it's only a matter of time before a cat ends up dead or seriously injured. 

Am I the asshole here? I feel like I'm ruining what could be a great friendship with her new dog, but at the same time I dont want our cats to end up dead.

making my fiancee return her newly adopted dog