Clinical, pathological and parasitological examinations of a German spaniel with alveolar echinococcosis, Germany, 2018

Alveolar echinococcosis (AE) is a parasitic zoonosis occurring in most European countries and also emerging in parts of Asia and North America. AE is caused by the larval stage of Echinococcus multilocularis in intermediate and also in accidental hosts. The principal definitive host is the red fox, but domestic dogs and cats are also potential definitive hosts. Several species of rodents serve as intermediate hosts of this parasite. However, there are also some species acting as accidental intermediate hosts, among them dogs. Since the late 1980s cases of canine AE have been diagnosed. Here, we present a case of canine AE in a two-year old female intact German spaniel from Thuringia, Central Germany. The dog was used as a hunting dog and presented to a small animal clinic for subacute lethargy and inappetence. Abdominal ultrasound and contrast computed tomography (CT) scan were performed and revealed intrahepatic lesions. Multinodular changes of the liver and the greater omentum were demonstrated by exploratory laparotomy. After euthanasia, a necropsy was performed and histological sections of representative tissue samples were prepared. PCR followed by sequencing was conducted with DNA extracted from tissue samples of the liver, hepatic lymph nodes and greater omentum. The sequence herein obtained showed very high similarity with other partial nad2 sequences of E. multilocularis from the GenBank database by BLASTn analysis and was analysed using the maximum likelihood method. The presented case combines the clinical presentation and pathological, parasitological and phylogenetic analyses.