Bone cancer in large and giant breeds frequently presents as lameness misdiagnosed as orthopaedic disease. Recognising red flag signs enables earlier diagnosis and better welfare outcomes.
Dogs with osteosarcoma typically present with progressive lameness that does not respond to NSAID treatment as expected for common orthopaedic conditions. Pain is severe and often disproportionate to the apparent degree of lameness. The welfare cost of delayed diagnosis is weeks of undertreated pain in a disease where early palliation significantly improves quality of life. Any large breed dog with progressive lameness that fails to respond to appropriate NSAID doses within 7-10 days should have radiographs taken to exclude bone tumour before continuing symptomatic management.