Diagnostic utility of D-dimer and peritoneal fluid cytology in traumatic reticuloperitonitis in bovines

Traumatic reticuloperitonitis (TRP) is a prevalent and economically significant thoraco-abdominal disorder in bovines caused by ingestion of traumatic metallic foreign bodies leading to reticular perforation and septic peritonitis. Due to overlapping clinical features with other gastrointestinal disorders, diagnosis often remains challenging. This study aimed to assess the diagnostic utility of peritoneal fluid cytology and D-dimer concentration in bovines with confirmed TRP. Peritoneal fluid was collected from six affected and six healthy bovines, and evaluated for gross appearance, total protein, red and white blood cell counts, and D-dimer levels. Cytological smears stained with Giemsa were semi-quantitatively scored for polymorphonuclear cells (PMNC), mononuclear cells (MNC), fibrin, red blood cells (RBCs), and bacteria. TRP cases exhibited significantly elevated total protein (p<0.01), RBCs, total leukocyte and neutrophil counts (p<0.05), and D-dimer levels (p<0.05) compared to controls. Cytology revealed increased PMNC scores and decreased MNC scores (p=0.0022), with significantly higher fibrin deposition, bacterial presence, and RBC infiltration (p<0.05). A strong positive correlation (ρ = 0.926, p = 0.033) between tube clot test and D-dimer concentration indicated active fibrinolysis concurrent with peritonitis. Based on cytological scoring, cases were stratified into mild, moderate, and advanced septic TRP stages, with findings ranging from sterile exudates to marked neutrophilic infiltration, fibrin clumps, and intra-/extracellular bacteria. This study demonstrates that the integration of peritoneal fluid cytology and D-dimer estimation provides a rapid, minimally invasive, and field-applicable diagnostic approach with high clinical relevance. The semi-quantitative cytological scoring system developed herein enhances the accuracy of TRP diagnosis and staging, particularly in field conditions where advanced diagnostics may be unavailable. Overall, this multimodal approach improves the early identification and management of septic peritonitis in bovines, reducing diagnostic ambiguity and improving prognosis.