Alveolar hydatid disease (Echinococcus multilocularis) in the liver of a Canadian dog in British Columbia, a newly endemic region

Abstract

An adult dog that lived in central British Columbia was examined because of a history of lethargy and vomiting. Histology, immunohistochemistry, and polymerase chain reaction (PCR) examination of a hepatic mass confirmed the presence of an alveolar hydatid cyst, the first description of Echinococcus multilocularis in British Columbia. We provide recommendations for case management and remind practitioners in endemic areas of western Canada that dogs can serve as definitive and, rarely, intermediate hosts for E. multilocularis.

Figure 1

Longitudinal ultrasound image of the left liver. Note the liver’s irregular surface, mixed echogenicity and cavitated lesions within.

Figure 2

Photograph of the resected hepatic mass. Notice the multiple generalized coalescing white nodules that appear to infiltrate hepatic tissue. Bar = 3 cm.

Figure 3

Photomicrograph of a section of cystic tissue from the mass shown in Figure 2. Note the 3 intraluminal protoscolices surrounded by a thin membrane. The cyst is lined by a hyaline membrane (“laminated layer”). Hematoxylin and eosin, Bar = 50 μm.