Gross, microscopic, and imaging findings of congenital malformations in farmed caimans ( Caiman yacare )

Congenital malformations (CMFs) are structural disorders that arise during embryogenesis, and various forms of these abnormalities have been reported in reptiles. The yacare caiman ( Caiman yacare ) is widely used in commercial farms in the Pantanal region, and studies characterizing CMFs in these animals are scarce. This study describes the pathological and imaging findings of CMFs in farmed caimans. From February 2022 to February 2023, the incubation and maternity of a caiman commercial farm, operating in ranching and farming systems, were monitored. A total of 26 distinct CMFs were identified in 30 farmed caimans. All animals were classified as infantile (9.65 ± 2.69 cm snout-vent length). CMFs were grouped according to anatomical site, with craniofacial disorders (18 cases) being the most frequent findings, followed by spinal malformations (13 cases). Palatoschisis (PC) and cheiloschisis (CL) were reported in 6 yacare caimans, which also exhibited a malformed palatal velum and secondary aspiration pneumonia. Meningoencephalocele was diagnosed in 3 caimans, with brain hemorrhage being a typical secondary lesion in these cases. Anophthalmus, exophthalmos, and cyclopia represented the ocular CMFs. Spinal malformations (kyphosis and scoliosis) were detected in 13 yacare caimans and were thoroughly characterized by the X-ray radiographic analysis. Tail abnormalities were reported in 12 animals, including tail agenesia (1 case) and coiled tail (11 cases). Other sites of CMFs include the limbs, the coelomic wall, and the skin. Radiographic assessments were obtained from all 30 CMFs, providing detailed information on these lesions.