Gross and histopathologic findings in sheep with plastic bags in the rumen.

The objective of this study was to evaluate the gross and histo-pathological lesions caused by plastic bags in the rumen of sheep. Sixteen (16) castrated, one-year old Dorper sheep were used for the study. The animals were divided into 4 groups each consisting of 4 sheep. Three of the groups had 129 g, 258 g and 387 g of plastic bags, respectively, introduced into the rumen through rumenotomy, while the fourth group, without implants served as control. All the animals were observed daily for 6 weeks following implantation. All animals were euthanized on day 42 and subjected to gross and histopathological examination. Gross changes observed at post mortem included; atrophy of the muscle and body fat, atrophy and fibrosis of the spleen, liver, kidneys and hydropericardium. Gross lesions in the rumen included stunting, atrophy, thinning and loss of ruminal papillae, erosion, ulcerations and nodular formation on the ruminal mucosa. Histopathological examination revealed atrophy, ulceration, erosion and disruptions of the stratified epithelial layer of the papillae. Other changes included parakeratosis, hyperkeratosis, prominent rete pegs, oedema and severe hydropic degeneration of different parts of the mucosal layer. There was increased mononuclear cell infiltration, increase in the number of lymphatic vessels and lymphangiectasis in the submucosa and oedema in the muscularis and serosal layers. The pathological changes observed contributed to clinical signs and may interfere with the absorption of nutrients resulting in poor condition of the animal, and loss of production and productivity.