Please Help My Dog Rek From Dying!

I need help , does anyone know of any places that have sponsorship or financial help for medically needed surgery for our beloved dog Rek. He was hit by a car and needs his leg amputated asap but unfortunately we do not have the funds and are being turned away. It's $4,000.00, if we dont get some help with in the next couple days we will have to give him away to the humane society where he can get the help he needs and we may not be able to get him back. Hes our best friend and family companion. Please please help and share. Thank you so much.