Feasibility of a rapid on-farm hepatic ultrasonography protocol in sheep with suspected chronic fasciolosis.

Abstract

Hepatic fasciolosis represents a major health and production concern in sheep farming. Although ultrasonography has been used to evaluate fasciolosis in ruminants, the feasibility of a rapid ultrasonographic protocol performed in standing sheep under field conditions has not been specifically described. This study aimed to provide a preliminary, descriptive evaluation of the feasibility of a fast on-farm ultrasonographic protocol for the assessment of hepatic alterations in sheep with suspected chronic fasciolosis. Sixteen Sarda sheep with Fasciola hepatica fecal eggs count > 100 eggs per gram underwent clinical examination, hematological tests, and liver ultrasonography. Three sheep were slaughtered, and their livers were examined by gross pathology and histopathology. The median duration of the ultrasonographic examination was 2.5 min per animal. Recurrent ultrasonographic features included heterogeneous parenchymal echotexture and echogenicity (87.5 %), irregular diaphragmatic liver surface (68.8 %), moderate to severe bile duct dilatation (50 %), and thickened gallbladder walls (56 %). In a subset of animals (37.5 %), intraluminal structures compatible with adult flukes were visualized within the biliary tract. Pathological and histological findings in the necropsied animals were consistent with the ultrasonographic features observed in vivo. This study provides preliminary descriptive evidence that a rapid hepatic ultrasonography protocol is feasible under field conditions in standing sheep with suspected chronic fasciolosis. Further prospective studies are required to clarify the diagnostic performance and clinical utility of ultrasonography in ovine fasciolosis.