Multiple congenital malformations in a burrowing owl (Athene cunicularia) from Southern Brazil

Abstract This study reports a case of multiple congenital malformations in a burrowing owl ( Athene cunicularia ) rescued in southern Brazil. Clinical assessment revealed partial agenesis of the forelimbs, bilateral asymmetric syndactyly, and selective anonychia of the second digit in both pelvic limbs. Despite severe locomotor limitations and the inability to fly, the individual maintained a satisfactory body condition score, demonstrating the species’ adaptive and behavioural capacity. The integrity of the epithelial tissues and the symmetry of the digital alterations support a teratogenic etiology, distinguishing the condition from traumatic lesions. The absence of macroscopic chromosomal abnormalities suggests that these anomalies may be associated with environmental factors or point mutations. This report highlights the importance of wildlife rehabilitation and triage centers in detecting sentinel alterations, serving as an alert for wildlife conservation regarding potential environmental contaminants that may impair embryonic development in anthropogenic landscapes.