I wanted to share this with other that may be facing a similar situation.  Begonias story was definitely unusual, and to this day, the doctors can offer no explanation as to why she was able to survive as long as she did. I say it was a much needed miracle, lots of devotion to her care and answered prayers. Hersymptoms were VERY sudden. She was happy and playing one evening and the very next morning (October 15, 2008)she acted as if she has a broken front leg. SHe could not put any wieght on it. I immediatley took her to our local country vet. After having taken several xrays of the leg, I was told that she most likely had developed bone cancer in her left front forearm. Her xrays looked like a moth eaten bone, which explained why she had no stability in that leg. It wasnt actually broken at this time, but a pathlogic fracture was probably imminent. We were told about our options for her , which included amputation of the leg (which was not reccomended for this large of a breed), Chemotherapy (which was not avaialble in our remote location of Wyoming), or uthanization. At this time Begonia was about 6 1/2 years old. Other than her leg, this dog showed no signs of any other illness and had always been a healthy active dog. I was unable to bear putting her down at that time and asked out vet to cast her leg to provide stability and allow us some time to explore our treatment options. I contacted a veterinarian located in Decatur Texas (DR. Sterle)who has some experience with cancer such as this. In fact her own dog had bone cancer. I transported Begonia to Dr. Sterles office in November and she confirmed that the xrays did appear to show signs of bone deterioration and most likely Bone cancer.At this point. Begonia was being kept in a homemade splint made from 2" PVC pipe cut in half and lined with foam pipe insulation, wrapped with cotton padding and vet wrap.I use a big plastic serving spoon and attached it to the end of the splint to provide protection for her foot pad. It was quite the set up!.She was now being treated for a secondary infection partially due to her licking the sore leg and the heat generated from the bone tumor.We did a bone biopsy on that visit which clinically confirmed the diagnosis of "probable" osteosarcoma. i say "probable", because there is no difnitive test for bone cancer. The tumor on the leg had grown and was now visibly larger than the right leg. Begonia was on an agressive dose of antibiatics and pain medication for the next 3 months. She also received an IV treatment of pain meds and antibiotics. Although she toleratd the daily splint bandaging,, she really wanted it off. I decided after 3 months to see how she felt on the leg. To my surprise she barely had a limp. I took her back to the vet for more xrays and we were all shocked to see that the moth eaten bone areas seemed to be filling in with new bone material! This was great news, but baffling to all of the Vets, since you cant cure cancer with antibiotics. Begonia was weaned off of the antibiatics and pain killers over the next 6 weeks. She was really good for about a month and then the limp camp back and the swelling became larger. ALthough still a mystery, we decided to put her back on the anibiotics to control the infection that seems to flare up around the tumor. Begonia stayed on the heavy dose of antibiotics for the next 1 1/2 years and showed no signs of the tumor spreading until July 2010. This time the growth was very rapid. No amount or type of antibiotic was helping. I managed her pain on the leg with a variety of pain medications until May 2011. On Mothers day I made the decision to put my best friend to sleep. She was unable to sleep comfortably through the night and was also unable to get on and off the couch that she loved to sleep on. Begonia actually lived to be 9 years and 3 months old.This is old age for a St. Bernard. Truly a miracle given her prognosis at just 6 1/2 yrs. We miss her everyday, but im thankful to have had all of that extra time with her and knowing that she was happy to be with us and was not allowed to suffer.