Diagnosis and economic consequences of triclabendazole resistance in Fasciola hepatica in a sheep flock in south-east Scotland

Over the past decade, definite changes have been recorded in the regional prevalence, seasonality and severity of fasciolosis in the UK, related to increased rainfall, or localised flooding, prompting debate about the deleterious effects of climate change. As a consequence, effective management of fasciolosis has become problematic in areas where fluke traditionally exists, leading to serious loss of production in sheep and cattle. Meanwhile, in eastern districts, there have been unexpected outbreaks of disease, resulting in production losses and concerns about welfare. This case report describes the economic consequences of fasciolosis in a commercial sheep flock in south-east Scotland. The diagnosis and consequences of triclabendazole resistance are discussed, in the context of developing economically sustainable control strategies.