just want to vent and get inputs ...

so my boyfriend and I are expecting in march yay ! my first, his second. we just found out our dog has cancer in his leg and it’s been a rough couple of days. we had his daughter with us when we found out about the cancer and when my boyfriend was making the exchange (giving his daughter back to his ex) his daughter mentioned the dog was sick. my boyfriend and his ex got the dog together many years ago, but he was more my boyfriends then he was “theirs” and she hasn’t seen the dog in the past couple of years that we’ve had the dog or even asked about him. my boyfriends ex said she would like to be involved in the dogs life now and would like updates etc on what happens with the dog and the cancer “being that he was their dog originally” and here’s why I’m irritated - I have gone above and beyond for this dog. I was not a dog person until this one. money has been tight since my boyfriend was hurt at work and was waiting for workers comp checks so I paid for all the dogs vet bills, his shots, his license, and the most recent trip to the vet was a couple hundred dollars which we didn’t have so I opened a care credit card just for the dog. i’m a pretty understanding person but I’m getting sick and tired of her still being a part of our lives. am I being crazy or should she actually be a part of this ??