Are all dogs with a splenic mass diagnosed with hemangiosarcoma? This assumption often leads to client panic and a presumed poor prognosis. In this talk, we'll discuss how to approach owners before a diagnosis is confirmed, including when to raise suspicions and when it's less likely. We'll delve into the specifics of hemangiosarcoma, including diagnostic tips, surgical options, chemotherapy, and supportive care. Additionally, we'll explore the relevant statistics and the best ways to communicate them to pet owners. This lecture will also provide updates on new diagnostics that can help predict hemangiosarcoma and new therapies, as well as an overview of current chemotherapy protocols and supplements based on recently published studies.