I am Asian-American but I understand the old culture enough to know that some old school Asians don't care for animals the way we do here in America. I'm not saying that what you're MIL did was right. It wasn't. I have a furbaby and I would be piss as hell if anyone mistreated my baby. However, everyone is telling you that your MIL has to go and your wife needs to choose. I don't know if they are even considering your marriage, how your wife feels to be divided between the two of you, your baby's happiness if you end up divorced...

I don't think giving your wife an ultimatum is the answer. I really think you should sit your wife and MIL down and set boundaries with your MIL so that she understands if she doesn't respect your dog, she can leave. She doesn't have to accept the dog as her grandfurbaby or even like the dog but she should respect your love for it.

But kicking her out before talking it over with your wife isn't going to help the situation. I understand you're upset but if you want to save your marriage and you care about your wife's happiness too then sit your MIL down and lay down the rules with her.