Proliferative peritonitis with larval and cystic parasitic stages in a dog

A six year old Labrador mix dog, born in Spain, was imported to Germany in young age. After a period of vague abdominal pain and negative laboratory results, the dog was referred to a local veterinary clinic for laparotomy, where the tentative diagnosis of echinococcus alveolaris was made and the dog was euthanized. At necropsy, many cystic structures and a massive proliferative peritonitis were visible. Furthermore a few solid larval cestodal stages were found in the peritoneal and chest cavity. Histological the cysts contained a small eosinophillic tegument, a cell poor stroma, basophilic somatic nuclei and a variable amount of amorphous bodies. The solid cestodes exhibited a quite similar composition with neither scolices nor any head structures. Histological features of the parasitic stages resembled cysts and asexual stages of Sparganum proliferum. Distinctions to other larval cestode infestations in body cavities were discussed.