Help save our dog

I made a gofundme page to help my family dog have a life or death surgery needed immediately. Stryker is a 9 month old German Shepherd who recently delveloped parvo. We took him to two other vets who thought he had been poisoned since he had all of his shots and was current. Since he has vomited so much the past two days the vet said the only thing that will save him is doing surgery. Currently, he is on IVs at the vet hospital and my parents have already spent over $800. Trying to get him better. They can't get a care credit card due to my dad already using it for his eye surgery a few months ago. So they have no more funds. The vet said the cost will range between 3,600.00-5,000.00 Any help would be greatly appreciated. Stryker hasn't even begun to live yet and he is a loving family dog who has never hurt a flea. Please help and share if you can. He has to have the surgery asap or he will die. He is family, not just a pet. He holds a special place in our hearts and he needs a second chance.