Spontaneous Splenic Hemangiosarcoma in a Guinea Pig (Cavia porcellus)

An 18-month-old female guinea pig (Cavia porcellus) was presented with a 2-week history of inappetance. A 4 cm abdominal mass was palpated on physical examination. Radiographs were not able to identify the origin of the mass and an exploratory laparotomy was performed. The mass was found to be splenic in origin, occupying approximately 80% of the organ, and the spleen was removed. Histological examination and immunohistochemistry confirmed the mass to be consistent with a splenic hemangiosarcoma. Further examination of the abdominal cavity and thoracic radiographs of the guinea pig revealed no evidence of metastatic disease. Postsurgical survival was 17 months, with no radiographic evidence of tumor recurrence or metastases during that time. Spontaneous splenic hemangiosarcoma is rare in this species, but should be considered as a differential for an abdominal mass.