New consensus aims to redefine sepsis in dogs and cats

Veterinary emergency and critical care specialists have proposed a new consensus definition for sepsis in dogs and cats, aiming to replace the long-used “SIRS plus infection” model with a framework centered on life-threatening infection-associated organ dysfunction. In the new Journal of Veterinary Emergency and Critical Care consensus statement, sepsis is defined as “a life-threatening syndrome caused by a dysregulated host response to infection resulting in organ dysfunction,” and clinicians are encouraged to use formal illness-severity assessment with validated scores when identifying cases in practice. The effort brings small-animal medicine closer to the direction human medicine took with Sepsis-3, while trying to account for veterinary-specific evidence and limitations. (onlinelibrary.wiley.com)

The publication didn’t appear out of nowhere. In 2024, many of the same authors published a position statement arguing that veterinary medicine lacked a uniform sepsis definition and was still relying on modified criteria derived from the 1991 and 2001 human consensus conferences. That review said the inconsistency was hampering research, limiting translation of pathophysiology into practice, and making it harder to optimize patient care. It also laid out the core critique of SIRS-based recognition: the criteria are easy to apply, but they can generate false positives and false negatives, especially in critically ill animals where inflammation is common even without infection. (onlinelibrary.wiley.com)

That criticism has support in the veterinary literature. A 2024 Frontiers study evaluating new-onset organ dysfunction in dogs with systemic inflammation found that organ dysfunction, by itself, did not cleanly separate septic from nonseptic inflammatory cases, except that fluid-refractory hypotension was strongly associated with sepsis. But the same study also found that the presence of at least two organ dysfunctions was significantly more common in nonsurvivors, and that acute kidney injury, stupor or coma, prolonged prothrombin time, and decreased base excess were retained as mortality-associated variables. In other words, organ dysfunction may not be a perfect diagnostic shortcut, but it appears highly relevant to risk stratification and prognosis. (frontiersin.org)

The new consensus approach also reflects a broader shift in how the profession may think about case identification. Rather than leaning only on binary inflammatory cutoffs, the recommendation to use validated illness-severity scores points clinicians toward structured assessment tools already familiar in critical care research, including APPLE-based scoring systems for dogs and cats. Those tools were developed to stratify mortality risk in hospitalized patients, not specifically to diagnose sepsis, but they offer a more standardized way to quantify how sick a patient is at presentation. That could be especially useful in multicenter studies, referral hospitals, and high-acuity settings trying to compare outcomes across populations. (onlinelibrary.wiley.com)

Direct outside commentary on this specific paper appears limited so far, but the surrounding specialty community has clearly been preparing for implementation. VECCS has hosted education tied to “consensus definitions for sepsis in small animals,” and 2026 symposium materials list sessions on applying the consensus criteria and on sepsis management in dogs and cats. That doesn’t amount to independent endorsement, but it does suggest the specialty ecosystem is already treating the new framework as something clinicians will need to understand and operationalize. (veccs.digitellinc.com)

Why it matters: For veterinary professionals, this is less about semantics than about standardization. A clearer consensus definition could improve communication between ER, ICU, internal medicine, and referring teams; reduce variability in which patients are labeled septic; and make future trials more comparable. It may also help retire the older concept of “severe sepsis,” mirroring human medicine’s view that sepsis is inherently life-threatening once organ dysfunction is present. At the same time, clinicians should be cautious about overreading the change: current evidence suggests organ dysfunction is prognostically important, but not every organ dysfunction in an inflamed patient means infection is the driver. Clinical judgment, diagnostics to confirm or support infection, and serial reassessment will still matter. (onlinelibrary.wiley.com)

The shift could also influence antimicrobial stewardship and case documentation. The 2024 review emphasized that ideal confirmation of bacterial sepsis still depends on methods such as culture and susceptibility testing, even though culture has limitations and not all infections are readily confirmed. If the field adopts a more standardized sepsis definition while continuing to push for better infection confirmation, practices may be better positioned to balance early treatment with more disciplined classification of suspected versus documented infection. (onlinelibrary.wiley.com)

What to watch: The next key step is validation. Consensus definitions are useful, but they become most powerful when they are tested prospectively, adopted in multicenter datasets, and tied to practical bedside criteria that work in both specialty and general practice settings. Watch for follow-on studies, registry work, conference education, and any formal implementation guidance that clarifies which organ dysfunction measures and severity scores are most useful in everyday canine and feline sepsis care. (onlinelibrary.wiley.com)