Surgery to remove vulvar mass (Tumor in uterus)

Roxanne, my blue nose pitbull, has developed a tumor in her uterus and needs to have it removed. It's pushing the tissue from her vaginal cavity out making it hard and soon to be impossible to urinate . After a few different estimates the cheapest surgery I can find for her is going to be about $2, 500. I'm in desperate need of a miracle and don't want to lose my baby.