>Her spleen was huge (knew this prior to the surgery) and had a huge tumor >on it. He called it a hemangiosarcoma. He admits that he is not terribly >knowledgeable about these tumors in ferrets. Dear X: Rule #1: Don't get all worked up until biopsies come back - if necessary, you can always panic then. Actually, I cam currently working on a case of 15 hemangiosarcomas - three were in the spleen. One had disseminated hemangiosarcoma all over the abdomen, and that animal died, but when it was opened up at surgery, it was a mess, and there were no surprises. The other two hemangiosarcomas were confined to the spleen, the spleen was removed, and the animals did well. In dogs, this is a common tumor, and the prognosis is not good - many metastasize widely. I would like to thing that this is not the case in ferrets, and the prognosis is better, but right now we just haven't seen enough of these rare tumors. Could he be wrong? Sure. Not all big ugly black lesions on ferret spleens are tumors - some could be infarcts, which readily happen when the spleen is enlarged for any reason. I have had a number of infarcts submitted as tumors. It could also be a hematoma, from a rupture of a splenic vessel - these can be big and ugly. The key to spleens - it is really difficult for anyone, even pathologists with many years of experience, to tell grossly whether a splenic lesion is a neoplasm, a hematoma, an area of hyperplasia, etc. That's why we have microscopes. With kindest regards, Bruce Williams, DVM [Posted in FML issue 3664]