An eight-year-old Holstein cow presented to Cornell’s Equine and Farm Animal Hospital for mastitis un-responsive to treatment. She was referred to Cornell from her primary veterinarian following a six day history of mastitis, weakness, anorexia and drop in milk production. On presentation she was febrile (105.1F), tachycardic (HR 96 beats/min), moderately dehydrated and had bilateral hemorrhagic sclerae. Her udder was warm, firm, hyperemic and asymmetrically swollen and her milk was yellow and watery with white flakes. Initial blood work revealed several hematological and biochemical abnormalities suggestive of systemic inflammation including an inflammatory leukogram. Further hematology the following day revealed toxic changes in neutrophils, thrombocytopenia, hypokalemia, hypocalcemia, hypomagnesemia and hypoalbuminemia. The patient was bolused IV fluids to restore volume deficit, administered flunixin meglumine as an anti-inflammatory and anti-endotoxin and was started on intravenous oxytetracycline as an antimicrobial. She was also given oxytocin and all four quarters were milked out every four hours with hand stripping when necessary.