Prevalence and Pathology of Ovine Dicrocoelium dendriticum Infection at an Organized Farm in Kashmir

A retrospective study was undertaken to investigate the prevalence and pathology of Dicrocoelium dendriticum infection in sheep at an organized farm in Kashmir. During the years 1996 to 2010, 163 sheep belonging to different breeds, ages and sexes were observed to have livers infected with Dicrocoelium dendriticum. Adult females were more severely infected than young ones. The occurrence was more severe from September to February, followed by May and June. Clinically, the affected sheep were dull, emaciated and anaemic. Post-mortem examination revealed the livers to be pale, friable or firm having depressed irregular whitish lines giving the surface uneven appearance. Histologically, biliary hyperplasia, periportal fibrosis coupled with aggregates of inflammatory cells of lymphocytes, monocytes and eosinophils in periportal and portal triads was a dominant finding. One adult female sheep revealed cholangiocellular carcinoma characterized by multiple yellowish-white firm nodular growth which histologically showed proliferating biliary ducts and ductules lined by multilayered cuboidal or columnar cells. The study indicated that Dicrocoelium dendriticum has a pathogenic and oncogenic potential and needs to be controlled to avoid losses to sheep industry.