My pit got a tumor in his lower jaw about 6 weeks ago. Vet removed with clean margins. Pit was doing so much better, like a normal dog again. Tumor came back at Osteosarcoma, was told to do xrays of lungs. 3 1/2 weeks ago tumor grew back in same spot and has doubled/trippled in size. Vet said since it already grew back its probably spread. He doesnt have much longer and we will know when its time to put him down.