Help Barrett get the surgery he needs

I’m not normally good at asking people for help, but in this case I really need it.
This is Barrett, he is a 9 y/o Lab/Rottie mix and he is my absolute life. 
He recently tore his Cranial Ligament in both of his back legs and needs to have surgery to reposition the joint and put screws and a plate on it to keep it in place. 
It’s about 3,600 per leg, and I’m barely getting by for just myself.
Any little bit helps me.
hes currently on strong pain medications and anti-Inflammatory  to help get him by until I can pay for the surgery.
thank you so much, from both Barrett and I.