Tracking Systemic Inflammatory Progression in Dogs: Blood Indices as Predictive Tools

Aims: To evaluate the alterations in haematological indices such as neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and systemic immune-inflammation index (SII) in dogs diagnosed with systemic inflammatory response syndrome (SIRS), and to further assess the changes in these parameters in cases that progress to multiple organ dysfunction syndrome (MODS). Study Design: The study was conducted over a 12-month period and included dogs that met the inclusion criteria for SIRS. Blood inflammatory indices were recorded and interpreted. Place and Duration of Study: The study was conducted in the Department of Veterinary Clinical Medicine. Ethics and Jurisprudence, College of Veterinary and Animal Sciences, Pookode, Wayanad- 673576 between July 2024 and June 2025. Methodology: Dogs meeting the inclusion criteria for SIRS were enrolled in the study. Based on organ dysfunction parameters, they were categorized into two groups: Group I, comprising dogs that did not develop MODS, and Group II, comprising those that progressed to MODS. Comprehensive haematological analyses were performed and their relevance in disease progression was interpreted. Results: NLR values were significantly elevated in both groups compared to the control group (6.3 ± 0.93 in Group I, 8.09 ± 0.86 in Group II, and 3.28 ± 0.14 in controls). Although PLR values did not show a statistically significant difference between Group I and the control group, Group II exhibited a significantly lower PLR (90.21 ± 16.65) compared to controls (169.15 ± 16.14; P = 0.003). SII values were markedly increased in both groups relative to the control animals. Conclusion: The study highlights the prognostic significance of NLR, PLR, and SII as inflammatory biomarkers in dogs with SIRS, with notable differences observed between those that developed MODS and those that did not.