HI TS, there are deeper issues with your marriage other than just the pet.

this happens to many marriages, especially Asian and many people are just unwilling to speak about it. so you are one of the rare ones who are willing to talk about it.

the long answer is that you need to firstly ask yourself what are the deeper issues with your marriage.

the usual suspects are

1) reduce or lack of communication.

2) Different interest between the partners.

3) spark reduce due to too long together and lack of glue to hold the partner together. normally kids or common interests will hold the partner together but seems you are lacking both.
short answers is that if you are really contemplating divorce, you need to consult a lawyer first and slowly start to separate your financial assets.

i have friends that got cleaned out by the angry wife due to divorce and this was even before the proceedings started