Alpha-mannosidosis in goats caused by the swainsonine-containing plant Ipomoea verbascoidea

Abstract

A disease of the nervous system is reported in goats in the semiarid region of northeastern Brazil. Histological examination showed diffuse vacuolation of neurons and epithelial cells of the pancreas, thyroid, renal tubules, and liver. The swainsonine-containing plant Ipomoea verbascoidea was found on both farms where the goats originated. This plant was experimentally administered to 3 goats, inducing clinical signs and histologic lesions similar to those observed in spontaneous cases. On the lectin histochemical analysis, cerebellar cells and pancreatic acinar cells gave positive reactions to Triticum vulgaris agglutinin (WGA), succinylated Triticum vulgaris agglutinin (sWGA), Lens culinaris agglutinin (LCA), Canavalia ensiformis agglutinin (ConA), Pisum sativum agglutinin (PSA), Ricinus communis agglutinin (RCA(120)), Arachis hypogaea agglutinin (PNA), and Phaseolus vulgaris erythroagglutinin (PHA-E) suggesting storage of α-fucose, α-D-mannose, α-D-glucose, β-D-N-acetyl-glucosamine, N-acetyl-galactosamine, and acetyl-neuraminic acid. This pattern of lectin staining partially agrees with results previously reported for poisoning by swainsonine-containing plants. The chemical analysis of dried leaves of I. verbascoidea detected swainsonine (0.017%), calystegine B(1) (0.16%), calystegine B(2) (0.05%), and calystegine C(1) (0.34%). It is concluded that I. verbascoidea causes α-mannosidosis in goats.