Pathology in Practice

Alveolar echinococcosis in a dog in the eastern United States

“…Collectively, these findings are typical of infection with the larval stage of Echinococcus multilocularis . 3,8,14,15,21…”

“…However, gross morphology is not different from hepatic neoplasia or other inflammatory or proliferative hepatic diseases. 8…”

“…4). 3,8,15,21 Other Echinococcus spp. also produce PAS-staining membranes, but the appearance of a multichambered structure growing invasively in normal tissue is most characteristic of E. multilocularis .…”

“…Final confirmation of E. multilocularis infection in cases of AE is made by either species-specific PCR analysis of fluid aspirate or biopsy material or by genus-specific PCR and genotyping. 2,3,8,15 These tests are available through a limited number of academic and reference laboratories.…”

“…15 Since then, additional cases have been detected in Canada, mostly in Alberta, Saskatchewan, and Ontario, a province that previously had not been considered in the parasite’s endemic range. 8,17,18 Surveys have detected E. multilocularis in up to one third of coyotes in Alberta 11 and Ontario. 9 Only 2 haplotypes of E. multilocularis had been recognized in North America, one in Alaska and the other in the north-central United States.…”