Case Report

Intra-abdominal bleeding in a horse: not always of traumatic origin

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Abstract

A nine-year-old warmblood mare was presented with clinical signs of mild colic and fever. On percutaneous ultrasound of the abdomen, a mass was identified on the left side of the abdomen between the spleen and the stomach. During examination the following day, intra-abdominal blood was observed. On rectal examination, a mass was palpated in the pelvis. The presumptive diagnosis of hematoma with intra-abdominal bleeding was made. On consecutive ultrasounds and radiographs, the mass evolved in shape and other masses were identified in the liver and the lungs. No change was noticed in the pelvic mass. Cytology and histology of a tru-cut liver biopsy revealed abnormal, most likely neoplastic cells, whereas cytology of the abdominal and thoracic fluid did not reveal any neoplastic cells. Due to the presence of several rapidly growing masses, a neoplastic process was most likely. Because of the malignant character of the disease and the persistence of the clinical signs, euthanasia was suggested but refused by the owner. Supportive treatment was instituted. Initially, the general condition remained stable, after which the horse suddenly collapsed and died. Post-mortem examination revealed a primary neoplasm located in the pelvic cavity, as well as multiple disseminated masses within several tissues. The mass found in the liver had ruptured with loss of probably 50 liters hemorrhagic fluid within the abdominal cavity. Based on gross pathology, cytological and histological findings, a hemangiosarcoma was suspected. This diagnosis was confirmed using immunohistochemistry for von Willebrand factor. In this case report, the importance of differentiating hematoma from hemangiosarcoma in the horse is highlighted.