Evaluation of serological changes of ESR, CRP, IL-6 and tumor necrosis factor-alpha (TNF-a) and hematologic parameters in pet dogs with pyometra

Canine pyometra is associated with systemic inflammation, but erythrocyte sedimentation rate (ESR) has been less extensively evaluated alongside cytokines, C-reactive protein (CRP), and routine hematologic variables. This case-control study compared inflammatory and hematologic measurements in 15 dogs with closed pyometra and 15 clinically healthy controls. Interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), CRP, ESR, white blood cell (WBC) count, packed cell volume (PCV), and serum creatinine were assessed. Group differences were analyzed using independent-samples t-tests, with Welch correction when variance heterogeneity was detected. Mean differences were reported with 95% confidence intervals and Hedges' g effect sizes. Dogs with closed pyometra had higher IL-6, TNF-α, CRP, ESR, and WBC counts and lower PCV and serum creatinine than controls (all p ≤ 0.005). The largest standardized differences were observed for ESR (g = 2.39), PCV (g = −2.29), and serum creatinine (g = −1.94). Within the pyometra group, IL-6, TNF-α, and CRP were strongly correlated (r = 0.974–0.978; p < 0.001). These findings demonstrate a pronounced systemic inflammatory and hematologic phenotype in closed canine pyometra and identify ESR as a potentially informative component of multimarker inflammatory assessment. Prospective studies incorporating longitudinal measurements and clinical outcomes are required to determine diagnostic or prognostic utility.