Causes and Outcome of Systemic Inflammatory Response Syndrome in Dogs: An Observational Study of 172 Cases

To evaluate the clinical characteristics, underlying diseases, organ dysfunctions, and survival of dogs with systemic inflammatory response syndrome (SIRS) or sepsis.

Prospective observational study from January to December, 2023.

Single-center, veterinary university teaching hospital.

One hundred sixty-six dogs; six dogs with distinct cases of SIRS were included twice (172 cases).

None.

Dogs were included if they met two or more of the four SIRS criteria (hypothermia or fever; tachycardia; tachypnea; leukocytosis, leukopenia, or left shift) and had a disease causing systemic inflammation. Cases were categorized into groups (G) "nonseptic SIRS" (G1: n = 73), "sepsis" (G2: n = 92), "sepsis without organ dysfunction" (G2a: n = 25), "severe sepsis" (G2b: n = 59; dysfunction of one or more organ systems), "septic shock" (G2c: n = 8; hypotension despite adequate fluid resuscitation), and "SIRS of unclear origin" (G3: n = 7). The most common causes of SIRS/sepsis were gastrointestinal diseases (n = 61 [35.5%]), vector-borne diseases (n = 28 [16.3%]), and neoplasia (n = 22 [12.8%]). There was dysfunction of one or more organs in 114 cases (66.3%). The coagulation system was most frequently affected (n = 78 [45.3%]), followed by the cardiovascular system (n = 47 [27.3%]), respiratory tract (n = 14 [8.1%]), kidney (n = 13 [7.6%]), and liver (n = 6 [3.5%]). Overall, 128 of 165 cases (77.6%) survived until discharge (short-term), and 116 of 159 (73%) survived ≥4 weeks after discharge (long-term). Differences in outcome were found between G1 and G2 (short-term: p = 0.046, long-term: p = 0.015), with dogs in G2 having better survival. Short-term mortality was higher in cases with one or more organ dysfunctions than in cases without (p = 0.031).

SIRS can be triggered by a variety of diseases in dogs. Strict and regular monitoring is important for early detection of organ dysfunction.