First isolation of Dicrocoelium dendriticum among cattle in some Northern Algerian slaughterhouses

Dicrocoelium dendriticum or small liver fluke often causes unnoticed clinical manifestations in cattle. For a live animal, its diagnosis is mainly based on the detection of eggs by coproscopic examination. The objective of this study was to determine the presence or absence of Dicrocoelium spp. never previously reported in the study area but also to establish its prevalence, as well as an association between dicrocoeliasis and sex, age and season of the year, and histological characteristics.

The study was carried out in slaughterhouses of three districts (Bouira, Tizi-Ouzou, and Bejaia) from January 2017 to December 2017. To this end, of 4053 cattle, representing more than 10% of the total number of animals slaughtered, stool and bile samples were collected and a liver inspection was carried out to investigate lesions of distomial cholangitis. They were processed for histological analysis. The specimens were morphologically identified according to the orientation of the testicles, the length and width of the body, and the level of the maximum width of the body.

The total prevalence of dicrocoeliasis obtained of the 4053 cattle inspected is 0.52% with a prevalence of 0.66% in Tizi-Ouzou, 0.54% in Bouira, and 0.27% in Bejaia. About 0.52% of livers had distomial cholangitis (21 of the 4053 livers examined had adult D. dendriticum and 15% had non-distomial cholangitis. About 0.25% of cattle had D. dendriticum eggs in the stool versus 0.52% of cattle had parasite eggs in the bile. Statistical analysis revealed no significant association between dicrocoeliasis infection and the season of the year (p>0.05). However, a significant association was found between dicrocoeliasis infection and sex and age of the animal (p<0.05); females and older animals are more likely to have dicrocoeliasis. Histological analysis of the fluke revealed an anterior positioning of the testicles with a slightly oblique tandem orientation, an average body length of 3.69 mm and an average body width of 1 mm. The maximum body width level is either in the middle of the fluke body or in the rear position.

The histological study confirms that the collected fluke is D. dendriticum. Thus, this work reveals for the 1^st time in Algeria the presence of D. dendriticum in three districts (Bouira, Tizi-Ouzou, and Bejaia). The results indicate that many cattle farms in the North Central Province of Algeria are infested with D. dendriticum.