We remember Lazaro Spallanzani (1729-1799) mainly for his controversy with Needham over spontaneous generation, but he was a man of multiple scientific activities in the fields of biology, mineralogy, physics, mathematics and… volcanology! Called "the biologist of biologists", he developed a series of investigations about reproduction of amphibian, in one of them -Experiences in service to the history of the generation of animals and plants- we have found horrific experiments with frogs, including severe and useless mutilation of males, in order to interrupt its copulation with females, acts he describes as "barbaric", and we estimate inadmissible in the ecclesiastic man he was, even in an epoch in which animals were considered "anima vili" (something without value). A brief review of the use of animals in laboratories shows significant advances in the ethical regulations for this practice, but we believe that these achievements are not enough.