Abstract
The margay (Leopardus wiedii) is a neotropical, arboreal wildcat widely distributed in Brazil. Since 2014, it has been classified as Vulnerable on the National List of Endangered Species (ICMBio) and listed as Near Threatened by the IUCN. Morphological studies of wild felids are essential for understanding their ecological and functional adaptations to their environment. Anatomy is a fundamental tool for investigating aspects related to species biology and evolution, particularly interactions with the environment, diet, and reproduction. This report describes the renal morphology and vascularization of Leopardus wiedii, with a focus on potential clinical and surgical applications, including vascular anastomoses, imaging studies, nephrectomies, and preoperative planning to minimize complications. The animals were formalin-fixed at the Laboratory of Teaching and Research in Morphology of Domestic and Wild Animals at the Federal Rural University of Rio de Janeiro, injected with colored latex, and dissected. The right kidney measured 4.68 × 2.55 × 2.34 cm and the left kidney measured 4.47 × 2.73 × 2.59 cm in animal 01, and the right kidney measured 3.32 × 2.10 × 2.34 cm and the left kidney measured 3.69 × 2.26 × 2.20 cm in animal 02. Single renal arteries were observed bilaterally, with a single renal vein on the left and double veins on the right. These findings enhance the anatomical knowledge of the species and support its clinical and conservation management.