Should I Just Leave the Relationship for Good?

Earlier in our relationship, we discussed not getting a dog. We compromised and got a cat because there less maintenance. But once we broke up, he let me know that he was going to get a dog. So i eventually decided to give us ther chance to handle our relationship differently. Now the dog still exists, and it's driving me insane. Should i keep pushing for him to get rid of a pet that could easily end up being his lifelong best friend? Cause, the lord knows a dog won't leave you, but i will. What should eman do? I don't care.