[warrior1]

I am so sorry. Osteo is a terrible and painful cancer. My boy had it in the front leg as well and yes, the tumor seemed to come out of no where. Please think hard before having a biopsy. Have you had a chest x-ray? That will tell if it has spread to his lungs. Monitor his activity very closely as he run's the risk of fracturing that leg. Sadly enough, many of us here have lost our dogs to this awful disease. I am glad you have sent off your x-rays for a second opinion. Best of luck to you and your boy. Please keep us posted.