Help Murray run again! Knee surgery

Murray has never been the most 'athletic' dog. Even as a little puppy, he had a more calm and relaxed personality than our little puggle, Ginger. She was the escape artist, and Murray was content laying with you on your lap and being pet. As he got older, we noticed that he seemed less capable of walking longer distances, and would often stop and want to turn back- although, he never seemed in pain. Now, at just over 6 years old he can hardly walk at all. Over the summer, we noticed that he was a bit slow to stand up, his back legs lagging. My family never though anything unusual of it, because he still didn't seem in pain, and has always been a bit slower in his movements. Very rapidly, over the past few months- he has gone from a bit slow to stand, to not able to even take stairs or run. He can hardly even walk 10 feet on a walk without having to stop and sit down- but he always tries to get back up and keep going, still excited to be out on a walk.Initially, the vet thought it was just arthritis. But after his problems became more serious they took some x-rays and found that his knee bones are extremely deformed- some of the worst the vet has seen. It is most likely genetic, although he will soon be going to see a specialist for more information. The vetrinarian said that he is most likely in a lot of pain, his knee caps are entirely out of place and his knees have even developed bone in places where there should be none. No dog should endure this amount of pain- any pain, and not sweet Murray- who is only 6 and a half. He is seriously one of the calmest and sweetest dogs you could know, and we want help him as soon as we can. After going through the surgery- which he will need in both of his knees- it will most likely take around 6 weeks for him to recover. The current price estimate is $8000 for the surgery. I will update this information after he sees the specialist.This has come so suddenly, and no one in my family was prepared for this financially. Any help at all would make myself and my family extremely, extremely grateful. I am looking forward to the day that Murray is able to run and play with his best friend Ginger again.