Our dog Rusty starting going lame several weeks ago, the vet thought it was ligament damage and we got anti-inflammatory drugs. Today Rusty had an x-ray and we were told he has cancer in one of his rear knees. (Canine Osteosarcoma) Has anyone gone through this? What treatment did you decide upon, or did you go with no treatment (amputate vs. drugs for pain), and how did your dog respond? The vet said it is easier for a dog missing a back leg instead of the front, but it is almost inevitable that the cancer will get him in the end. This is so hard to deal with and we are just clueless how to handle it!!! So if anyone has gone through this and it isn't too painful, we could really use some help.