Gross and Microscopic Morphological Anatomical Study of the Guinea Pig (Cavia porcellus) and the Capybara (Hydrochoerus hydrochaeris), Aimed at the Preparation of a Comparative Anatomical Atlas of the Different Systems

In recent years, there has been an exponential increase in the so-called “new pets”, including the domestic guinea pig (Cavia porcellus) and the capybara (Hydrochoerus hydrochaeris), two closely related Caviid rodents native to South America. Both historically bred for food purposes, they have more recently become increasingly popular as pets in the European and American continents, respectively. This led to an increasing veterinary interest in deepening the knowledge regarding their normal anatomy, as a basic contribution to other fields of veterinary medicine, including diagnostic imaging, surgery, and pathological anatomy. Being part of a bilateral framework co-tutelage agreement leading to a joint Doctoral Degree between the Alma Mater Studiorum of Bologna, Italy and the Universidad Nacional del Litoral of Santa Fe, Argentina, this research project was partly carried out in Italy (study of guinea pigs) and partly in Argentina (study of capybaras). It consisted in the macroscopic study, through anatomical dissections of carcasses of both species as well as the use of anatomical casts, and in the histological study of the various systems in the two species, and was aimed at creating a gross and microscopic comparative anatomical atlas. From the gross and microscopic morphological and morphometrical anatomical study of the different system of the guinea pig and capybara, several analogies and differences emerged. The creation of a comparative anatomical atlas of gross and microscopic anatomy of the capybara and the guinea pig might prove useful for clinical, zootechnical and research purposes.