Advice regarding dog

Any advice on how to ask ex avoidant to see the dog? for context - was in a four-year serious relationship and ex had a dog. he got to keep her because he bought her about six months before we met. break up was meant to amicable but he turned really cold post break up and is also now in a new relationship (started dating his colleague a month post after we broke up). i have been hurt and havent been able to reach out but now feeling healed. want to see the dog but dont want ex thinking im reaching out to see him. i also don't want to disrespect the new gf's feelings (not that it's really my problem...).

is this worth breaking no contact? I feel really sad and guilty that i've neglected the dog. she was my best friend and it's just sad.