Haemorrhagic lesions were observed mainly on the rectal mucosa (Fig. 6). Numerous eggs were found in the
mucosal scraping. The lamina propria was thick and inflammed and in some cases there was marked
granulomatous response around eggs, which was characterized by the infiltration with epitheloid cells and
proliferation of fibroblasts (Fig. 7). These findings were almost similar to the observations of Singh and Parihar
(1990). Adult parasites live in the mesenteric blood vessels where they lay eggs. The eggs have spine. From the
mesenteric vein the eggs lodge in the intestinal capillary and break the capillary wall to enter into the intestinal
lumen. During this migration the spiny eggs sets up an inflammatory reactions around the eggs (Soulsby, 1965).
Probably thus they produce haemorrhages in the intestine. Possibly these inflammatory reactions call-forth
inflammatory cells such as eosinophils, lymphocytes, macrophages and plasma cells which provokes
granulomatous response. In most of the parasitic infections, eosinophilic infiltration is mainly seen. On the other
hand, granulomatous inflammation is produced in long standing chronic cases. Perhaps at first exposure, adult
parasites themselves and their eggs and other products and byproducts cause sensitization. In the subsequent
infection, profound granulomatous response occurs in those sensitized animals. Fibrous proliferation usually
occurs in response to fibrogenic cytokines produced by sensitized T cells (Meeusen, 1999).