Sheep abomasal phytobezoariasis: the effect of breed, season and age with histopathological observations

The prevalence of the latent form of sheep abomasal phytobezoariasis and the effect of husbandry management on this condition were determined in a survey in and industrial abattoir in Urmia from June 2005 to July 2006. The effect of different age groups and seasons on the prevalence of sheep abomasal phytobezoariasis was also determined. Furthermore, the histological changes in the affected abomasal tissue were also verified. The breeds and ages of the sheep were identified prior to slaughter. In the postmortem, the abomasum was examined for foreign bodies, including bezoars. Tissue specimens were taken from the abomasal body in the affected cases. The annual prevalence of sheep abomasal phytobezoariasis was 1.95%. The prevalence was highest in the Makuei breed and the lowest in Ghezel sheep. The prevalence was higher in winter compared to other seasons. The number of phytobezoars per abomasums ranged from one to four. The histopathological changes in the affected cases included leukocytic infiltration in the mucosal layer, edema, glandular hyperplasia and cystic spaces.