Effect of praziquantel on histopathology in experimental porcine schistosomiasis

Indigenous piglets, 2-month old and of either sex were infected each with 1 500 cercariae of Schistosoma incognitum by tail method and were divided,int o 2 groups. The first group was treated with praziquantel @ 25 mg/kg body w eight on 21 st DPI while second group was kept to study infected untreated control. Additionally, 2 piglets from same litter were kept as uninfected u ntreated healthy control. The animals were sacrificed on 47-52 DPI and stud ied for gross pathology; tissues were processed in acetone-benzene paraffin series and 5 mu sections were studied after staining with haematoxylin and eosin. Grossly, lungs of infected untreated animals showed hyperaemia and emphysem a. The liver was enlarged, congested with grayish foci over the surface whi le severe congestion of mesenteric blood vessels was observed in the intest ine. The treated animals showed either mild or absence of these features. M icroscopic studies revealed inflammatory reactions, distension and rupture of alveoli, hyperplasia of peribronchial lympboid tissues in untreated infe cted animals while treated animals showed mild emphysematous changes with a bsence of peribronchial hyperplasia. The liver of infected untreated animal s had perivascular infiltration and degenerative changes in the hepatocytes which were absent in the treated animals with subsiding inflammation in pe rivascular area. A chronic inflammation with sloughing of intestinal epithe lium was observed in untreated, infected animals while no such reaction cou ld be observed in treated animals.