Haemonchosis and haemoparasites of small ruminants reared in north western, Nigeria

Abstract

Small ruminants (goats and sheep) production systems worldwide are significantly constrained by haemo and gastrointestinal parasites. The study was carried out in Northwestern Nigeria from November 2011 to October 2012 with the aim to identify the common haemoparasites and haemonchosis in small ruminants. Three hundred abomasum samples with corresponding blood samples were collected from 200 goats and 100 sheep, respectively at necropsy. The abomasa were examined by Hansen and Perry method for the presence of Haemonchus contortus while blood samples were examined using the thin blood smear and Haematocrit Centrifugation Techniques (HCT). The prevalence of Haemonchus contortus in small ruminants was 80.3% with goats and sheep having prevalence of 78% and 85%, respectively. The prevalence for H. contortus in small ruminants during late dry, early dry, late rain and early rain were 64.9%, 84.1%, 89.9% and 81.1%, respectively. The prevalence were statistically significant among the seasons (p<0.05) with highest prevalence in the late rainy season. The total number of adult worms collected was 21862. The highest adult worm burdens were obtained during late rainy season (August to October) when a mean worm burden of 180.2 ± 51.45 and PCV of 26.63 ± 0.63 were recorded. The mean worm burdens for early dry, late dry and early rain were 42.60 ± 6.93, 31.67 ± 5.56 and 61.10 ± 11.33, respectively. The PCV values for the season were 27.73 ± 0.79, 26.60 ± 0.87 and 28.40 ± 0.65, respectively. The values of PCV for the four sub-seasons were not significant from one another but the value of PCV obtained during early rain was different from those of other sub-seasons. The PCV had a weak negative correlation with worm burdens with Pearson correlation coefficient of -0.2632 which was highly significant (p<0.001). Out of 200 goats and 100 sheep examined for haemoparasites, only one goat had heavy infection with Trypanosoma vivax and a sheep had mixed infection with Theileria ovis and Anaplasma ovis. The prevalence of three protozoans encountered was 0.33% each in small ruminants. The PCV of infected goat and sheep with protozoan parasites was 25% and 20%, respectively. The results suggest that Haemonchus contortus may be the major cause of anaemia in the study area. It is therefore recommended that further research be embarked upon to determine the effect of nutrition in ameliorating the effects of helminth infections and anaemia in small ruminant.

Keywords: Haemonchosis, Haemoparasites, Prevalence, Small ruminants, Sub-seasons