An eight month old swamp buffalo calf has exhibited symptoms of anorexia, weakness and debility before death. Post mortem examination of gastrointestinal tract revealed presence of few parasites in the abomasum only. Abomasum is one of the specific locations for bursate nematodes of Trichostrongylidae family. Gross examination of the abomasal mucosa revealed presence of oedema, petechial haemorrhage and nematode parasites. Nematode parasites were identified as Haemonchus contortus after clearing in Lactophenol. For histopathological studies, tissue samples of abomasum with lesion were fixed, processed and stained by haematoxylin and eosin. Microscopic examination of stained tissue sections showed presence of degeneration, sloughing and necrosis of the lining epithelium; haemorrhage in the blood vessels of the muscular layer and infiltration of eosinophils in the sub-mucosal layer. Atrophied gastric glands and glandular degeneration were also observed.
