Ninas leg operation

Nina is our rescue dog that we have had for about a year and a half now. She is the cutest, daftest and most loyal dog. Unfortunately she needs cruciate ligament surgery ASAP due to her being in a lot of pain and struggling with walking. 
I would never usually do anything like this but found myself with no other option, with the unexpected fees being so high. Any help would be massively appreciated. 
The X Ray on her leg was £650 and the specialist consultation fee is £240 plus the operation being £4,250.  
Thankyou so much.