Encysted cyathostomin larval counts: Mucosal digestion revisited

This study sought to evaluate spatial variation in encysted cyathostomin larval counts among the large intestinal organs and their subsections. Following humane euthanasia, ceca, ventral, and dorsal colons were harvested from 8 foals (aged 4-8 months) raised in an anthelmintic naïve parasitology research herd. Each organ was weighed and separated into 3 equal sections by length: the orad, intermediate, and aborad portions. From each of those sections, two 5% weight tissue samples were collected and digested to quantify the early third stage larvae (EL3) and late third stage larvae/fourth stage larvae (LL3/L4). A mixed model statistical analysis was carried out to evaluate for differences of larval counts among the different organs, sections, and the interaction term between the organs and sections. There were significant differences among organs (P < 0.0001), with the ceca having higher counts than the ventral and dorsal colons. However, there were no significant differences among the three defined organ sections (P = 0.1076). Coefficients of variation (CV) were all calculated to be greater than 1, suggesting a high level of variability among the samples; the least amount of variation can be found in the cecal data with a CV of 1.4024 compared with the ventral colon’s 1.529845 and dorsal colon’s 3.339135 within the respective organ. The following sections had the highest mean counts of encysted larvae: intermediate cecum, orad ventral colon, and aborad dorsal...
Source: Veterinary Parasitology - Category: Veterinary Research Source Type: research