Αcute visceral cysticercosis caused by Taenia hydatigena in lambs: ultrasonographic findings

Abstract

Background Cysticercosis caused by cysticercus tenuicollis is a metacestode infection that affects several species of ungulates. It is caused by the larval stage of Taenia hydatigena, an intestinal tapeworm in dogs and wild canids. In the intermediate host, the mature cysticerci are usually found in the omentum, mesentery, and peritoneum, and less frequently in the pleura and pericardium. The migrating larvae can be found mostly in the liver parenchyma causing traumatic hepatitis in young animals. Most infections are chronic and asymptomatic, and are diagnosed at the abattoir. The acute form of infection is unusual in sheep and reports of death in lambs are rare. Methods In March 2018, fifteen female lambs presented anorexia, weakness, lethargy, and death secondary to acute visceral cysticercosis. Twelve of them underwent hepatic ultrasonography. Examinations were performed on standing or left lateral recumbent animals. Results Livers of affected animals presented rounded margins and a thickened, irregular and hyperechoic surface. Hepatic parenchyma appeared to be wholly or partially affected by lesions characterized by heterogeneous areas crossed by numerous, irregular, anechoic tracts ranging from 1 to 2 cm in length and 0.1 to 0.2 cm in width. Superficial and intraparenchymal cystic structures were also visualized. The presence of lesions was confirmed by anatomopathological examination, and T. hydatigena cysticerci was identified by morphological and molecular characterization of isolates. Conclusions Our results highlighted that hepatic ultrasonography is effective for an intra-vitam diagnosis of acute cysticercosis in lambs.

Acute cysticercosis caused by Cysticercus tenuicollis in lambs

“…A study reported on 12 lambs with acute cysticercosis caused by C. tenuicollis which were diagnosed via ultrasound examination 11 . The livers of the lambs had round, thick, irregular, and hyperechoic edges.…”

“…Intra‐parenchymal cystic structures were also identifiable. Hepatic cysts were up to 0.4 cm in diameter and surrounded by damaged tissue 11 . In ultrasound examination, damaged tissues around the cysts were identified as heterogeneous parenchyma.…”

“…In the present study, unlike another study, diagnosis was made using necropsy. 11 Eight lambs and 3 goat kids died in an outbreak in Iran. 12 At necropsy, cystic hepatitis caused by C. tenuicollis was detected.…”

Shapes of pathology

“…In sheep, migrating larvae of Cysticercus tenuicollis (Corda et al 2020) and immature flukes of Fasciola hepatica (Cullen & Stalker 2016) cause serpiginous tracks in the liver parenchyma. The serpiginous tracks represent acute traumatic lesions caused by the wandering of immature helminths.…”

Taenia lynciscapreoli in semi-domesticated reindeer (Rangifer tarandus tarandus, L.) in Sweden

“…There are at least three types of metacestodes relevant to semi-domesticated reindeer ( Rangifer t. tarandus ) in Fennoscandia. First, Taenia hydatigena typically forms cysticerci that are usually found in the omentum, mesentery, and peritoneum but rarely also in other nearby organs in a range of ungulates ( Corda et al, 2020 ). Although T. hydatigena probably does not infect humans, infected organs should not be used to feed canids, because when the adult tapeworms grow, they can spread the infection within a reindeer population.…”