IL6 and systemic inflammatory response syndrome: In dogs, IL‐6 is reliably increased in models of sepsis and systemic inflammatory response syndrome, but IL‐6 concentrations tend to normalize within 6 days of an inciting inflammatory event, whereas other acute inflammatory markers such as C‐reactive protein and tumor necrosis factor α (TNF‐α) remained increased for 14 to 21 days after the inciting event.34