Rose's vet bills

I wouldn't normally do this but I need help. Rose is my boyfriend's 13 year old pitbull. She was rescued from a puppy mill where she was bred against her will for years and has had a hard life. She stopped eating and drinking these past few days and last night she fell down a flight of stairs trying to go outside. We went to the vet and found out that she has very severe arthritis and her liver is failing. We are doing everything we can to keep to her comfortable and make her last days easy for her but her medication is not cheap.  Any little bit would help get her the care she deserves. Thanks!