Retrospective evaluation of coyote attacks in dogs: 154 cases (1997-2012).

OBJECTIVE: To describe the clinical presentation and outcome of known attacks in client-owned dogs caused by the common coyote, Canis latrans.

DESIGN: Retrospective observational study.

SETTING: Private referral hospital.

ANIMALS: One hundred fifty-four client-owned dogs known to be attacked by coyotes.

INTERVENTIONS: None.

MEASUREMENTS AND MAIN RESULTS: Records from a private referral hospital from May 1997 through December 2012 were reviewed. Time of day and month/season of year, signalment, body temperature, heart rate, respiratory rate, body weight, location and severity of wounds inflicted, common injuries, length of hospitalization, necessity of surgical wound repair under anesthesia, antimicrobial use and mortality were recorded. Eighty-six percent of dogs presenting following coyote attack weighed <10 kg. Overall mortality rate was 15.6%. Dogs with bite wounds to the thorax had the highest mortality at 21.3%. Criteria for systemic inflammatory response syndrome (SIRS) based on admission vital signs were met in 58.8% of dogs and the presence of SIRS was significantly associated with mortality (P < 0.001). Common coyote-induced injuries included rib fracture (38/154; 24.6%), pulmonary contusion (30/154; 19.4%), tracheal tear (18/154; 11.6%), pneumothorax (16/154; 10.3%), abdominal wall hernia (9/154; 5.8%), and abdominal penetrating wounds (8/146; 5.5%). Dogs <10 kg were significantly more likely to incur wounds to multiple body parts or sustain abdominal penetrating wounds. The presence of rib fracture was significantly associated with mortality. Frequency of coyote attacks over the time of this study increased by 330%.

CONCLUSIONS: Coyote attacks on dogs are a problem in Southern California and are associated with substantial morbidity and mortality, especially in dogs with wounds to the thorax. Aggressive management involving surgical wound repair was associated with survival to discharge.