Title: Is it cancer? Use of a blood-based test as an aid-in-diagnosis for cancer detection in dogs. Description: What do you do when a dog presents with an abdominal mass that you can’t access for FNA or biopsy? How about a case where cytology or histopathology is inconclusive, but you still suspect cancer? What about a situation where you recommend biopsy, but the owner objects because they feel it is too invasive? When a dog is suspected of having cancer, the workup can take many forms and a variety of testing modalities may be needed to arrive at a definitive or presumptive diagnosis. This session will review a novel tool in the clinician’s toolbox – liquid biopsy – a test that evaluates a blood sample for the presence of circulating tumor DNA which indicates the current presence of cancer in the body. This session will review the basic principles of liquid biopsy testing and how this technology may be useful as an aid-in-diagnosis. A series of illustrative case samples will be presented, demonstrating how liquid biopsy has been used in the evaluation of dogs with suspected cancer.