My Wife's [35F] behavior towards dog feels unacceptable. Should this be a sign I[33M] should end it?

My wife really wanted a dog a few years ago. I never wanted one - it was simply too much work and I didn't see any value added to my life from it. But countless instagram videos of cute dogs convinced her that it would be an amazing, happy thing. So she got one, getting me to tacitly agree to it (I can be a pushover). I agreed to do my best to train the dog, since she wasn't sure how she might do that. And I tried, and several folks say our dog is well trained. While she got the dog, I gradually assumed primary ownership. Not by choice but simply because she didn't/couldn't handle him. I didn't mind that, but I do feel a little resentful that so much extra work was added due to her choice. My wife has said frequently she regrets getting the dog, and even talked of rehoming him. But I never agree to that because it's against my principles.

He's a very energetic, greedy 5 year old. He countersurfs and steals food, chews on things destroying toys and furniture. Today, my wife, who works from home, got frustrated after this behavior all day.

When I came home, she began ranting to me, and soon it turned into screaming after the dog stole some food meant for our baby again. She was pissed and wanted to punish him. She put him in his crate forcefully. And then screamed that he needed to be rehomed. And that if she just tells animal control that he bit her, they'll euthanize him. Our dog never bites anyone out of anger. But when he's been excited, he's occasionally jumped and grabbed our arms with the jaw, like a bite and it can hurt. This is usually very predictable - it happens when we jump or dance or run in the house.

So for an hour, she screamed at him, and screamed at me too. How I didn't train him (I did what I could), how I wasn't at home and went to work for a "shitty job" which didn't pay enough (she's said that before and then clarified that she always means I could do so much better). I was constantly under stress. Even our 3 year old son was stressed.

The way she behaved with the dog, is how she behaves with me frequently. It just so happens that the dog was at the receiving end today.

Just based on this behavior, what are your thoughts on my wife as a person? Would you be forgiving and understanding at this? Or deem this entirely unacceptable? I'm asking about this situation specifically because it doesn't really involve me. It's about her behavior with the dog.

In our relationship, we've been through a lot of conflict. I'm suffering. But I can't process ending what we have because of a few reasons. I have a 3 year old and I am worried about not getting sufficient custody. I'm worried she runs away to her home country with the kid or harms herself. I am worried about jobs and expenses and responsibilities. And my wife, when she's not "crazy", acts like she's sorry and never meant any of this.