Systemic Inflammatory Response Syndrome, Sepsis, and Multiple Organ Dysfunction Syndrome

The systemic inflammatory response syndrome (SIRS) and sepsis are common and associated with high morbidity and mortality in dogs and cats. Identifying the underlying cause of SIRS and, specifically, differentiating infectious from non-infectious causes of SIRS is vital to guide appropriate and timely treatment. Multiple organ dysfunction syndrome (MODS) is a multifactorial phenomenon that occurs secondary to both non-infectious SIRS and sepsis, and refers to the presence of altered organ function in an acutely ill patient such that homeostasis cannot be maintained without intervention. It is generally MODS that causes mortality in dogs and cats with SIRS and sepsis. The diagnostic approach to patients with SIRS and sepsis includes a complete physical examination, laboratory evaluations, diagnostic imaging, and often cytology or culture to identify an underlying infectious agent. Treatment for SIRS and sepsis includes treating shock, supportive care, and managing organ dysfunction(s). Treatment for sepsis should also include early appropriate antimicrobial therapy and source control when possible. Prognosis for dogs and cats with SIRS and sepsis is variable, but the presence of multiple organ dysfunctions is a poor prognostic indicator.