Pet: Theodore, Neut. Male, 9 years old, Chow-Mix

Timeline:

7/4/14- Theo started limping. We chalked it up to sprain while playing fetch.

7/11/14- Still limping. Vet visit- x-ray reveal significant arthritis. Pain Meds given.

7/24/14- Limping continues, and now includes significant soft tissue swelling around the front right carpus. Vet xrays again, still just significant arthritis. Start Aqequan injections.

8/11/14- Adequan not helping. Not longer weight baring on front right leg, vet suggests we see Orthopedic specialist.

8/15/14- Orthopedist takes new x-rays, says he is unsure about the diagnosis based off the presentation (i.e. lack of central lesion, presentation of the lesion only on the surface of the bone, and low grade appearance). We proceed with a FNA.

8/21/14- FNA biopsy reveals osteosarcoma. We schedule amputation.

8/26/14- Amputation complete. Limb sent out for histopathology report.

9/4/14- Meeting with Oncologist over pathology report shows diagnosis as metastatic bone cancer (carcinoma cells found), not osteosarcoma. Oncologist proceeds with ultrasound and full examination. No tumors found. Oncologist wants to proceed with chemo as though pathologist got it wrong, and treat for osteosarcoma based on the location of the original bone lesion.

So my question is, should we seek a second opinion? Is there a chance everyone has it wrong, and could this be a different cancer entirely that may not be behaving like any of the clinical presentations? My gut is telling me this was behaving differently, especially given it's low grade appearance, and maybe the amputation alone solved the problem. We are definitely in favor of chemo, but the vets can't even tell us what we're treating.

Theo was a perfectly healthy dog before he started limping. He hasn't lost any weight or had any other health issues. Also, should add that there are not visible lung mets since yesterday's scan.

Thank you for your consideration!

Rachel