Plasma procalcitonin concentrations predict organ dysfunction and outcome in dogs with sepsis

Background: Procalcitonin (PCT) is a valuable prognostic biomarker in human sepsis that is predictive of organ dysfunction, septic shock and mortality. Data on PCT in dogs is limited. This study aimed to investigate the prognostic value of baseline and serial PCT measurements in dogs with sepsis and to determine the association between PCT and sepsis severity and the presence of organ dysfunction. PCT concentrations were measured in citrated plasma samples collected from 53 dogs with sepsis at the time of admission (T0, n=53) and at 24 h (T1, n=35) and 48 h (T2, n=30) post-admission using a commercial ELISA. Dogs were classified by sepsis severity (sepsis without organ dysfunction; severe sepsis; septic shock) and outcome (survivors; non-survivors). Organ dysfunctions were recorded at T0 and during hospitalization, and the APPLEfastscore calculated at T0. Healthy dogs (n=12) were used as controls. Results: There were 18 septic dogs without organ dysfunction, 24 dogs with severe sepsis and 11 with septic shock. Baseline PCT concentrations were significantly greater in dogs with sepsis compared to healthy controls (P<0.0001), and in dogs with septic shock compared to dogs without cardiovascular compromise (P=0.01). Baseline PCT was significantly correlated with organ dysfunction (P=0.003). Declining PCT concentrations were documented in survivors at T1 and T2 compared to PCT at T0 (P=0.0006), and PCT clearance at 24 h was significantly higher in survivors (n=38) compared to non-survivors (n=15) (P=0.037). Canine APPLEfastscore was not predictive of sepsis severity, the development of MODS or outcome. Conclusion: In dogs with sepsis, PCT concentrations at hospital admissions are predictive of organ dysfunction and septic shock. Serial procalcitonin monitoring may offer valuable prognostic information in canine sepsis, wherein early decreases in PCT concentrations are associated with survival.