Hi, I know what you are going through, Dexter our dog got diagnosed with osteosarcoma 12 days ago, and it was such a shock. We decided on amputation straight away, not because we are under the illusion it might not have spread but to take his pain from the tumour away and also to give him a chance of maybe having few more months, without us having to maybe rush to have him pts in the event of a break or pain that meds can't touch. No one knows how long they have with this, but time is of the essence if you are going to amp as in Dexter's case alot changed in 4 weeks up until diagnosisx Good luck