I recently came across an story that really hit home for me, especially after hearing from friend that her beloved dog possibly has cancer. I know that when she told me, I immediately told her to make sure she gets a second opinion and speaks with specialists.
The story I came across talks about a family who was told that their sweet greyhound had osteosarcoma after having a blood clot between two of his vertebrae that was pressing against his spine removed. The vet originally told them that there was a 90 percent chance that it was nothing but took the precaution of sending it off for a biopsy.
When they returned to pick up their dog, the vet told them that the biopsy, verified by two pathologists, showed osteosarcoma, a painful and aggressive form of bone cancer. He recommended that they have their dog euthanized within days to save him the pain he would go through with this.