Tetrameres proventriculitis and renal nematodiasis infection in
Pelican from Melmaruvathur area of Tamil Nadu

Abstract:

Abstract
Background: The study evidenced mortalities of Spot-billed Pelicans Pelecanus philippensis between December 2021 and January 2022 in Chengalpattu Districts of Tamil Nadu, especially at Melmaruvathur region near Vedanthangal reserve of Chengalpattu District Tamil Nadu, India.
Objective /Case description: The carcasses were floating in the water and were performed post-mortem and samples were collected and sent to the central university laboratory for further confirmation of the outbreak. 200 birds died in the ponds. Gross lesions recorded were worms seen embedded in the mucosa of the gizzard, congested lung, liver, and kidneys. Samples were collected from necropsy for routine diagnosis. Virological examination revealed the samples were negative for NDV by RT-PCR and Pasteurellosis by isolation and identification revealed pulmonary congestion and hemorrhages. The liver revealed diffuse congestion of veins and sinusoids with multifocal periportal MNC infiltration. The lumen of the proventricular gland revealed globular-shaped gravid female Tetramers spp. High power view revealed thick–walled embryonated eggs in the uterus with first-stage larvae. Spleen revealed hemosiderosis. Kidneys revealed multifocal congestion and hemorrhages. Low-power examination of congested and hemorrhagic renal lobules with dilated medullary cones and ureters were noticed. High power examination revealed a cut section of numerous parasites. Parasites were mostly females with spines covering the tegument, a gravid uterus with numerous embryonated thick brown-walled operculated eggs consistent with the morphology of nematode Paratanaisia spp.
Conclusion
The histopathological findings in the proventricular and urinary tissue of infected birds suggested that Tetramers spp. Paratanaisia species in heavy loads have the pathogenic potential to cause mortality in naturally infected free-living Pelican birds.