Intoxication of llamas by Astragalus punae in Argentina

Several plants that contain indolizidine alkaloids, including swainsonine, are toxic to livestock, causing dysfunctional lysosomes and storage disease. Swainsonine induces a neurovisceral disease, known as locoism, in sheep, goats, and cattle, which occurs in several parts of the world, including, but not limited to, the western United States, China, and parts of Australia. In South America, locoism has been described in the Andean region of Argentina affecting sheep, cattle, and llamas. Intoxication by consumption of Astragalus punae was suspected in 4 llamas in Jujuy Province, northwestern Argentina. The grazing area contained abundant specimens of A. punae. The clinical course was similar to 15 d, and included moderate ataxia, incoordination of hindlimbs, and progressive loss of body condition. Microscopically, fine cytoplasmic microvacuolation was observed in the proximal convoluted renal tubules. Ultrastructurally, these changes consisted of severely dilated lysosomes. Swainsonine was detected in stem and leaf samples of A. punae at a concentration of 0.06%. Based on clinical history and signs, histologic and ultrastructural changes, and plant analysis, a diagnosis of swainsonine toxicosis caused by consumption of A. punae was made, which has not been reported previously, to our knowledge.

Automated summary

Several plants containing indolizidine alkaloids, including swainsonine, are toxic to livestock and can cause storage disease. Swainsonine induces a neurovisceral disease known as locoism, which occurs in sheep, goats, and cattle in various parts of the world. Locoism has been reported in the Andean region of Argentina, affecting sheep, cattle, and llamas. This study describes cases of swainsonine toxicosis in llamas caused by consumption of Astragalus punae, which has not been previously reported.