The aim of this study was to describe the bone changes observed after a daily oral administration of the calcinogenic plant <i>Solanum malacoxylon</i> (syn. <i>S. glaucophyllum</i>) (<i>Sm</i>) during 9 days. The Sm-poisoned rabbits had an increase of bone resorption in the endosteal surface of the cortical zone and an also in the surface covered by osteoblasts of the primary and secondary spongiosa of the trabecular bone compartment. Moreover, the epiphyseal growth plates in long bones appeared narrower than in the control rabbits, with reduction of the proliferative and hyperthrophic chondrocyte zones. The electron microscopic study revealed a significant decrease of proteoglycans in the hyperthrophic chondrocyte zone evidenced by a significant reduction of rutenium red positive granules in the poisoned rabbit. Altogether, these data suggest that cell differentiation may play a pivotal role in the pathogenesis of <i>Sm</i>-induced bone lesions.Facultad de Ciencias Veterinarias