Pulmonary tuberculosis in a captive giraffe (Giraffa camelopardalis)

Abstract

This study reports gross and histopathological findings in a 16-year-old pregnant female giraffe (≈13 months gestation) that died of systemic tuberculosis. Ante-mortem signs included anorexia, lethargy, weight loss, and weakness, which worsened despite supportive care. Postmortem examination revealed markedly enlarged, firm lungs studded with multiple grayish-white nodules throughout the parenchyma. Cut sections of lungs showed caseous, gritty areas consistent with chronic granulomatous inflammation. The heart was mildly enlarged with pale streaks and focal discoloration, suggesting degenerative and inflammatory changes. Histopathology of the lungs demonstrated classical granulomas with central caseous necrosis surrounded by epithelioid macrophages, Langhans-type multinucleated giant cells, lymphocytes and fibrous tissue, confirming tuberculosis. Adjacent lung tissue showed congestion and inflammatory infiltration. Cardiac sections revealed myocardial fibre degeneration, interstitial edema and mononuclear cell infiltration, consistent with myocarditis. Based on these findings, a diagnosis of disseminated tuberculosis with myocardial involvement was established. The occurrence in an advanced pregnant animal suggests that physiological stress and immunomodulation may have contributed to disease progression. This study highlights the importance of thorough necropsy and histopathological evaluation in detecting infectious diseases in wild species and emphasizes the potential for multisystem involvement in tuberculosis, complicating clinical presentation and outcomes.