A helminthological study was carried out from December 2010 to November 2011 in order to establish the epidemiology of Haemonchus contortus infections in small ruminants of Benin. A total of 756 abomasums, collected from randomly selected goats and sheep from all regions of Benin has been examined. An examination of the conjunctiva’s colour has been associated with parasitic diagnosis to assess the degree of anaemia in animals. The study disclosed an endemic evolution of haemonchosis. The overall prevalence was of 55.56% (SD= 0.50) with a mean burden of 175 worms per infested animal. No significant influence could be attributed to host’s species or age. The season has been a significant variation factor (p< 0.001). The prevalence of haemonchosis was higher in wet seasons (79.41% ± 0.40) than in dry (36.06 ± 0.48 %). The worm’s burden was also higher in rainy seasons than dry. Elsewhere, a strong correlation (p<0.001) was found between the conjunctiva colour and the worm burden but with a reverse influence of the season. In rainy seasons, degrees of anaemia have been low even though worm burdens were high. Inversely, moderate worm burdens induced detectable anaemia during dry seasons.

Key words: Haemonchus contortus, epidemiology, goats, sheep, Benin.