a survey on prevalence, species and pathologic lesions of ostertagia among slaughtered sheep in shahrekord region (southwestern of iran)

sixty sheep abomasums were randomly collected from shahrekord abattoir between april and september (2006). age and sex of the sheep were registered. all of the abomasums were transported to laboratory, nematodes, which were presented inside them, collected, and after calculating, their species and genus, were specified. abomasums that were contaminated by ostertagia or had gross damages were selected in order to sample microscopic sections (1×2 cm) and pathologic study.  forty-two (70%) of these abomasums were contaminated by gastro-intestinal nematodes. by minimum and maximum of counted ostertagia (67-1300) and mean of 127, thirty-two (53.33%) of abomasums were contaminated by ostertagia. also, eighteen (30%) of them were contaminated by two species of ostertagia circumcincta and ostertagia trifurcata. minimum and maximum of collected ostertagia was 85-1300 with the mean of 130. eight abomasums (13.3%) were only contaminated by ostertagia trifurcata with minimum and maximum of 67-230 and mean of 82. six abomasums (10%) were also contaminated by ostertagia circumcincta with minimum and maximum of 80-640 and mean of 110. there was a significant statistical relation between age and contaminating with ostertagia and maximal contamination had been seen between the ages six to twelve months (pvalue=0/005<0.05). by age increasing, the contamination was decreased. histopathological study of the abomasums contaminated by ostertagia had been shown that parietal cells were decreased because of parasitic larval infiltration and inflammatory cells such as neutrophils and eosinophils could be found in lamina properia.