Pathomorphologic changes in the ruminal acidosis of sheep]

Acute and subacute and spontaneous rumen acidosis was experimentally induced in 20 sheep and two lambs after feeding of barley, maize or glycose. The inner organs of those animals then were examined for morphological changes. The changes recorded from experimental acidosis were analogous to those observed after spontaneous outbreaks. Hyperaemia and blood leakage were macroscopically observed underneath the rumen mucous membrane which could be easily pulled off. The same signs sometimes were manifest in the third and second stomach as well. Pronounced edemas and hyperaemia occurred in the lungs, meninges (pia mater), and brain, and blood leakage was recorded from the epicardium. The histological findings included epithelial desquamation, infiltration of lymphocytes and leucocytes into rumen and fourth stomach (subacute) hepatitis (in 60 per cent of all cases), physical degeneration in the kidneys, and focal myocarditis (in 50 per cent of all cases). There were hyperaemia, edematisation, and blood leakage in the lungs, perivascular and pericellular edema in the brain, and severe hyperaemia of the meninges (pia mater) and thyroid gland. Those morphological changes were persistent and characteristic. Their relevance to diagnosis of rumen acidosis in sheep is undenied, provided that due consideration is given at the same time to the case history and paraclinical indices.