Encefalopatia associada à ingestão de Ipomoea pes caprae (Convolvulaceae) em bovinos no estado do Rio de Janeiro

Abstract

Poisonous plants are responsible for significant death in adult cattle from Brazil. Plants affecting the central nervous system, widely spread throughout the country, comprise over thirty poisonous species - notably the Ipomoea group, with two distinguish clinic syndromes: tremorgenic syndrome and “lysosomal storage diseases”. We describe, for the first time, natural and experimental Ipomoea pes caprae poisoning in cattle from a herd in the northside of Rio de Janeiro, Brazil. Clinical signs included episodes of intense ataxia, abnormal posture followed by falling, recurrent dorsal recumbence, and muscular tremor, contraction and spasticity, particularly in the limbs, intensified by movement and forthcoming. Cattles affected longer failed to recover. Grossly, a substantial amount of leaves and petioles was found in the rumen. Histopathology showed degenerated and necrotic neuronal changes, mostly in cerebellar Purkinje cells. Bielschowsky silver stain, Imunnohistochemistry with anti-calbindin, anti-synaptophysin, and anti-prion antibodies, and ultrastructural techniques confirmed those findings. Lectin histochemistry evaluation failed to demonstrate lysosomal storage in the affected neurons. The experimental poisoned calf displayed clinical signs similar to the natural case. In the 28º day of the experiment, the plant ministration was suspended and the calf recovered within four days.