Organ dysfunction and mortality risk factors in severe canine bite wound trauma

Abstract

Objective: To identify mortality risk factors, determine mortality rate, and to describe the treatment, incidence, and type of organ dysfunction in dogs with severe bite wounds. Design: Retrospective case study from 2000 to 2009. Setting: University veterinary teaching hospital. Animals: Ninety-four dogs admitted to the intensive care unit (ICU) with bite wounds. Interventions: None. Measurements and Main Results: In all dogs, physical parameters, diagnostic testing, surgery and anesthesia timing, and treatment details were recorded at presentation and during ICU hospitalization. The overall mortality rate was 15%. A majority of dogs (68%) were <10 kg. A majority of the wounds (53%) yielded no growth on bacterial culture. Prolonged time from admission to anesthesia was associated with a need for longer postoperative ICU hospitalization (P = 0.0099). Prolonged anesthesia time was associated with mortality (P = 0.0044). Systemic inflammatory response syndrome (SIRS) occurred in 54.3% of dogs and multiple organ dysfunction syndrome (MODS) occurred in 27.7% of dogs. The presence of SIRS was significantly associated with mortality (P = 0.01), with a mortality rate of 24% in dogs that developed SIRS. MODS was associated with risk of mortality (P < 0.001) with a mortality rate of 67% in dogs with dysfunction of 4 or more organs. Dogs with dysfunction of 1 organ system had a mortality rate of 9%. The body system most commonly affected was the respiratory system (37%). Cardiovascular dysfunction was highly predictive of mortality (odds ratio [OR]: 29). Conclusions: Patients with extensive bite wounds have a significant risk of developing severe secondary complications such as SIRS, disseminated intravascular coagulopathy, and MODS. Longer time to anesthesia was associated with a longer recovery and longer anesthetic times were associated with mortality, disseminated intravascular coagulopathy, and MODS. Injury to the respiratory system was most commonly encountered and mortality increased with cardiovascular injury, MODS, and SIRS.