Multimodal Postmortem Investigation of Fatal Thoracic Metallic Projectile Trauma in a Jindo Dog: Radiographic, Computed Tomographic, Necropsy, and Histopathological Findings

Metallic projectile injuries in companion animals present complex diagnostic and evidentiary challenges, especially when comprehensive crime scene data and intact projectiles are absent. This report describes the forensic postmortem investigation of an adult male Jindo dog submitted by law enforcement authorities following fatal penetrating trauma in South Korea. Digital radiography identified multiple radiopaque metallic opacities in the left thoracic region, accompanied by severe pleural effusion and subcutaneous emphysema. Postmortem computed tomography (PMCT; 16-slice MDCT, 0.75-mm slice thickness) precisely delineated clustered hyperattenuating metallic fragments embedded in the left thoracic wall, an oblique displaced fracture of the left fourth rib, marked hemopneumothorax with compression atelectasis, and pneumomediastinum, while excluding cranial or abdominal injury. At necropsy, approximately 100 mL of pleural blood was evacuated, and through-and-through pulmonary transcapsular lacerations were identified traversing the right and left cranial lung lobes. Multiple deformed metallic fragments were recovered adjacent to the fractured rib under strict forensic chain-of-custody protocols. Histopathology of pulmonary laceration margins confirmed acute hemorrhage, fibrin deposition, and early neutrophilic margination, establishing an acute antemortem vital reaction (survival interval < 1 h). Histological examination of the cutaneous entry and exit margins revealed mechanical tearing without thermal coagulation or soot residue, consistent with an intermediate-to-distant discharge. The anatomical convergence of lesions supported a right-to-left projectile trajectory, with the left axillary defect presenting features compatible with a shored exit wound. Death was attributed to fatal acute hemopneumothorax and bilateral pulmonary laceration secondary to perforating metallic projectile injury. This case demonstrates the indispensable diagnostic and prosecutorial value of integrating digital radiography, PMCT virtopsy, forensic necropsy, and histopathology in veterinary medicolegal investigations of non-accidental trauma.