A 9-year-old castrated Border Collie dog was examined at the Cornell University Hospital for Animals, Companion Animal Hospital on July 29, 2003 for dyspnea, lethargy and anorexia that developed during the past three days. Two months prior the dog had been diagnosed with lymphoma by lymph node aspirate, but further staging was not performed. The dog had been placed on a 10-week chemotherapy protocol including the drugs vincristine, l-asparaginase, cyclophosphamide, adriamycin and prednisone. During the initial physical examination the dog was tachypneic and dyspneic with harsh lung sounds. His peripheral lymph nodes were normal is both size and consistency. Neither cardiac murmurs nor arrhythmias were detected. All other physical examination parameters were within normal limits. The top differential diagnoses included relapse-lymphoma, heart disease, primary lung disease, and coagulopathy. Blood work from the referring veterinarian, 3 days earlier, revealed a normochromic normocytic non-regenerative anemia and a slightly elevated alkaline phosphatase of 256 U/L (reference range: 23-212). The results of a coagulation panel, including activated partial thromboplastin time, prothrombin time, and thrombin clotting time, were all within reference range.