Grasping at straws here, but is there any chance that you have pet insurance that covers EMERGENCY, LIFE SAVING SURGERY? I put the surgery part in caps because that is what our policy would require. I realize that this scenario probably would not work based on the dates you have provided, but figured it would not hurt to suggest it.

I think Plan A would be to try your hardest with the airline - and Plan B, to pay the change fees.

I wish your pet well. We are most definitely dog people and know all about pet surgeries and the follow-up home care (we used to have mini Dachshunds). Where we live in Canada, even spending $8,000 on surgery will only get you 4 days of hospitalization. After that it is a flat fee of $135 - $175 - even if all is that required is monitoring of your pet. It used to be the cost of boarding plus whatever nursing services your pet required. I have seen people break down in tears over this new "equalization" system. Who on earth could afford this - especially after the $8,000. I hope you manage to get a refund. Having a sick pet is just awful.