Dicrocoeliosis in extensive sheep farms: a survey

Antonio Scala,Giorgia Dessì,Claudia Tamponi,Silvia Carta,Andrea Corda,Giampietro Sedda,Ciriaco Ligios,Antonio Varcasia,Philippe Jacquiet,Giuliana Sanna

doi:10.1186/s13071-019-3609-2

Abstract

BackgroundThis study investigated the epidemiological and molecular aspects of dicrocoeliosis in extensive sheep farms.MethodsFrom 2013 to 2014, copromicroscopical analyses in 190 dairy sheep farms and anatomo-pathological inspections in six slaughterhouses were carried in Sardinia, Italy. Rectal faecal samples were analyzed using the FLOTAC® method, and anatomo-pathological examinations were based on detecting thickened terminal bile ducts (TTBDs). In addition, genetic analyses were conducted on representative DNA samples of adult Dicrocoelium spp.ResultsNinety-seven (51.1%) out of 190 sheep farms were coprologically positive for Dicrocoelium spp. In the liver, on the surface and cut surface, TTBDs were reported in 40.1% (309/770) and 15.3% (118/770) of the animals examined, respectively, with an overall prevalence of 25.5% (196/770). No intraspecific genetic variation was observed among the Dicrocoelium dendriticum isolates.ConclusionsOur survey reveals the widespread presence of D. dendriticum in Sardinia, although seasonal, geographical and climatic conditions might be key factors in modulating the infection prevalence. Examining typical lesions due to D. dendriticum in the liver in abattoirs can be used as a marker for tracking chronic dicrocoeliosis infection.

Highlights

This study investigated the epidemiological and molecular aspects of dicrocoeliosis in extensive sheep farms
Dicrocoeliosis is a disease caused by several species of the genus Dicrocoelium Dujardin, 1845 (Trematoda: Digenea), which live in the hepatic bile ducts and gallbladder of domestic and wild ruminants [1]
The pathological effects related to dicrocoeliosis in ruminants can sometimes be overshadowed by concurrent liver infections

Summary

Introduction

This study investigated the epidemiological and molecular aspects of dicrocoeliosis in extensive sheep farms. Dicrocoeliosis is a disease caused by several species of the genus Dicrocoelium Dujardin, 1845 (Trematoda: Digenea), which live in the hepatic bile ducts and gallbladder of domestic and wild ruminants [1]. Liver lesions due to dicrocoeliosis, such as abscesses, granulomas and fibrosis, as well as bile duct proliferation have been described in the New World camelids (llamas and alpacas) [2,3,4]. Production performance losses in animals are often not associated with dicrocoeliosis, as the infection remains underestimated in field conditions because of its subclinical evolution [13]. The pathological effects related to dicrocoeliosis in ruminants can sometimes be overshadowed by concurrent liver infections

Methods

Results

Discussion

Conclusion