2020 Volume 73 Issue 5 Pages 253-258
Three Japanese Black cows died suddenly in a herd of about 25 pregnant cows. Among that herd, six other cows developed respiratory symptoms and subcutaneous emphysema with fatal outcomes. All patient animals were fed sweet potatoes for three months prior to onset. Cows with respiratory symptoms showed elevated AST and γ-GTP, which suggested mild liver dysfunction. The gross findings in two dead cows were regression failure, emphysema and edema of the lungs, and ecchymotic spots on the surface of the liver. Microscopically we observed infiltration of macrophages and neutrophils filled alveolar spaces, proliferation of type II epithelial cells, pulmonary interstitial emphysema and localized hepatocellular necrosis. The sweet potato feed was moldy, blackened and damaged. We identified Fusarium spp. fungus from those sweet potatoes. We detected Ipomeamarone using high performance thin layer chromatography. From those results, we diagnosed this case as moldy sweet potato toxicity.
