Association of inflammatory markers elevation with aggressive behavior in domestic dogs

We tested the hypothesis that elevations of inflammatory markers such as C-reactive protein (CRP) and interleukin-6 (IL-6) could be associated with the presence of aggressive behavior in domestic dogs. Serum concentrations of CRP and IL-6 were determined by ELISA in eighteen adult male German Shepherd dogs showing no clinical signs but aggression. Eighteen healthy male dogs with a negative history of behavioral and neurological disorders were used as controls. Compared with normal dogs, those with aggression had significantly higher levels of CRP (P < 0.05) and IL-6 (P < 0.01) after adjustment for age, body weight, creatinine, blood urea nitrogen, total protein, total bilirubin and cholesterol. Our pilot data suggest for the first time that an activation of systemic inflammatory processes may contribute to the pathophysiology of aggression in domestic dogs. Further investigations are needed regarding the impact of our findings on treatment strategies.