Esophageal-Crop Capillariasis and Proventriculus Ventriculus Hystrichisiasis in a Migratory Duck (Anas crecca)

Background: The aim of the present study was to study pathological and parasitological characteristics of simultaneous capillariasis and hystrichiasis in a diseased Anas crecca captured in Mazandaran Province of Iran on Oct 2016. Methods: Parasitology and histopathology techniques were used to detect the parasites of the carcass of the captive common teal. Results: Macroscopically, severe chronic inflammatory reactions and nodular or granuloma formation and irregular thickening of the affected wall of the esophagus, crop, proventrculus and ventriculus were observed. Microscopically, apart from the chronic inflammatory reactions and granuloma formation, in the paraffin sections stained with Harris Hematoxyline and Eosin technique, the characteristics of the mature female and male Capillaria spp.  and their barrel-shaped operculated embryonated eggs were found within the tunnels burrowed by the nematode in the hyperplastic stratified squamous epithelium of the inflamed crop and distal portion of the esophagus. The mature female Hystrichis spp. containing oval-shaped, embryonated non-operculated eggs and male parasite were found within the labyrinthus spaces formed in the submucosa granulomas of the ventriculus and proventriculus. Conclusion: Based on the parasitological and pathological studies, the species of the nematode parasites were identified as Capillaria (Thominx) contorta and Hystrichis. tricolor.