Platelets are a vital part of the blood clotting system and interact closely with tumor cells. These interactions promote tumor growth and spread, but also alter the RNA content of platelets. These altered platelets are described as tumor-educated platelets because they carry this tumor signature to distant sites as they circulate through the body. RNA from platelets routinely collected in blood samples can be sequenced to identify the genes of origin. This platelet RNA profile can reliably distinguish human cancer patients with a wide variety of tumors from healthy people and patients with inflammatory disease. This study will perform RNA sequencing to determine the platelet RNA profile for dogs with several types of cancer versus healthy dogs and dogs with infectious disease. This will be a first step in developing a platelet-based minimally invasive cancer screening test.