Comparison of Sepsis-2 and Sepsis-3 definitions in a population of dogs admitted to a referral hospital intensive care unit: preliminary observations.

Objective: To compare systemic inflammatory response syndrome-based (Sepsis-2) and Sequential Organ Failure Assessment-based (Sepsis-3) definitions of sepsis in a population of dogs admitted to a small-animal hospital ICU. A secondary objective was to determine whether fulfilment of either definition was predictive of in-hospital mortality.

Methods: This was a prospective study. Clinical and clinicopathological data of 151 dogs entering an ICU at a university veterinary teaching referral hospital were prospectively collected over a total of 40 weeks, from March 1, 2020, through October 18, 2021, and used to retrospectively diagnose sepsis as per Sepsis-2 and Sepsis-3 definitions. We then evaluated the ability of Sepsis-2 and Sepsis-3 criteria to predict in-hospital mortality in this population.

Results: Of the 151 dogs admitted to the ICU during the study period, 20 dogs (13.2%) fulfilled the definition of sepsis according to Sepsis-2 criteria, whereas only 8 dogs (5.3%) met the Sepsis-3 criteria; only 2 dogs fulfilled both definitions of sepsis. All-cause in-hospital mortality of dogs fulfilling Sepsis-2, Sepsis-3, or both definitions was 40%, 62.5%, and 100%, respectively. Fulfilment of Sepsis-3 criteria was associated with a 4.6 times greater risk of in-hospital mortality compared to dogs who did not fulfill the Sepsis-3 criteria.

Conclusions: Sepsis-2 and Sepsis-3 criteria identified different populations of dogs. Fulfilment of Sepsis-3 criteria was associated with an increased risk of in-hospital mortality.

Clinical relevance: Further studies on the application of Sepsis-2 and Sepsis-3 definitions are required to further explore differences in phenotypic expression of sepsis in dogs and their impact on outcome.