This is the case study of a 5-year-old Ayrshire cow that presented with unusual complications from severe puerperal metritis. Prior to presentation, she had an emphysematous twin calf that was removed by caesarian section. She was subsequently referred to Cornell after unsuccessful treatment for a presumed peritonitis. Rectal and ultrasonographic exams revealed extensive fluid- and gas-filled cavities on both sides of the abdomen, as well as significant uterine adhesions. Bilteral flank laparotomies revealed large, fluid- and fibrin-filled retroperitoneal cavities displacing the abdominal organs cranially and ventrally. Due to the poor prognosis for recovery, the cow was euthanized. The findings at necropsy suggest that the source of these unusual dissecting pseuocysts was a severe necrotizing metritis. This seminar paper will present this case of unusual extension of metritis into the retroperitoneal space, as well as review the etiology, pathogenesis and treatment of metritis in post-partum dairy cows.