I put Charlie down the day after I wrote the first message. We took her to the vet and found out she tore her ACL. The vet explained the surgery, but fincally we could not afford it. The arthritis in the shoulders was also getting really bad. The vet said she would have to be on heavy doses of pain meds for the rest of her life, and I didnt think that was fair to her. It was the hardest decision I've ever had to make, and the worst experience of my life. But I know she is better now, and can run with no pain.

Thanks for the replies.