Malformations in neotropical viperids: qualitative and quantitative analysis - Sant'Anna, S. S; Grego, K. F; Lorigados, Carla Aparecida Batista; Pinto, Ana Carolina Brandão de Campos Fonseca; Fernandes, W; Sá-Rocha, Luiz Carlos de; Catão-Dias, José Luiz (Journal of Comparative Pathology, 2013)