The management of osteosarcoma in dogs focuses on both the primary and the secondary tumours.
Treatment: Primary Tumour
The ideal therapy would involve complete resection of the primary tumour and this most often requires amputation. Many dogs cope extraordinarily well following amputation but clearly there are some patients for whom this would be inappropriate. Concurrent neurological problems or severe arthritis constitute reasons for not considering amputation. Moderate arthritis can be managed extremely well with suitable medication and need not be a reason for not pursuing amputation; obviously this is an issue that should be evaluated on a case by case basis. Amputation invariably has a tremendous impact on the state of mind of the patient and while it is clearly a major operation, these patients seem to be so relieved to be free from the painful tumour that they recover extremely quickly.
In the event that amputation is considered inappropriate there are other options. For osteosarcomas of the distal radius (this is the lower front limb just above the wrist joint equivalent in dogs) an operation can be performed in which the tumour is removed and replaced by a custom titanium implant. The wrist joint then has to be fused so that the whole bone and metal construction can be stabilised adequately for dogs to go about their normal daily routines unaffected.
The objective of this procedure is to restore the dog to normal mobility in as short a time as possible. While this approach carries a definite appeal, it is critical to emphasise that the degree of tumour control afforded by this approach can at best be equivalent to amputation; there is also a risk of relapse of the tumour in the limb at the primary tumour site at some point in the future. More importantly, this procedure is associated with a high risk of complications, worst of which is infection associated with the metal implants.
For the patients in which amputation and the so-called limb-conserving surgery are not appropriate, palliative therapy can be administered in the form of radiotherapy and chemotherapy. The gold standard palliative therapy protocol involves the co-administration of radiation therapy on three out of four consecutive weeks with chemotherapy in conjunction with the first and final doses.
Surgical management of a bone tumour by resection of the primary tumour and replacement with titanium rod and plate implants