Cases of respiratory disease were diagnosed in five out of 23 cattle (21.7%) after they were fed moldy damaged sweet potatoes (Ipomoea batatas) on a small farm in the county of São Vicente do Sul, state of Rio Grande do Sul, Brazil. Of those five cattle, three died spontaneously and another one was euthanatized for necropsy while showing advanced respiratory clinical signs. The disease manifested itself approximately 24 hours after the ingestion of the sweet potatoes and lasted from 1 to 4 days. Clinical signs included dyspnea (labored breathing and abdominal respiration), tachypnea, extended neck with low carriage of the head and rhythmical flaring of the nostrils. Two cows were necropsied. Necropsy findings included distended pale and rubbery lungs which failed to collapse when the thorax was open, and marked pulmonary interstitial emphysema and edema. Lymphoid hyperplasia was observed in the hilar nodes and spleen. Histologically, the lesions were those of interstitial pneumonia. Alveolar septa were thickened by fibroblasts and inflammatory cells, and there was hypertrophy and hyperplasia of type II pneumocytes; the interlobular septa were distended by edema and emphysema. The culture of the moldy sweet potatoes yielded Fusarium solani and Fusarium oxysporum.
Toxic diseases; mycotoxicoses; respiratory diseases; interstitial pneumonia; diseases of cattle; sweet potatoes; Ipomoea batatas
