Help save my cat's life

My cat, Titan, was attacked by a dog, causing a ruptured tendon. This means he needs his back left leg amputated, and I need the funds by the end of the week or the veterinarian won't perform the surgery and I'll have no choice but to humanely euthanize him. That will kill me if that happens; Titan is my therapy animal he's seen me through some of the roughest times of my life so far. I don't want to part with him just yet. If you can give even a dollar it could make all the difference.