Objective—To analyze factors associated with interdog household aggression and determine treatment outcomes.
Design—Retrospective case series and survey.
Animals—38 pairs of dogs with interdog household aggression. Each pair of dogs was considered 1 case.
Procedures—Records of dogs with interdog household aggression that were examined during initial or follow-up consultations at a veterinary teaching hospital from December 5, 2006, to December 5, 2007, were analyzed for clinical features. Data regarding outcome, owner compliance, and efficacy of recommended treatments obtained by use of a follow-up survey were evaluated.
Results—Most cases (30/38 [79%]) of interdog household aggression involved same-sex pairs; 26 of 38 (68%) cases involved 1 female or a pair of females. Instigators and recipients of aggression were clearly identified in 27 of 38 (71%) cases; most instigators were the younger of the pair (20/27 [74%]) or were newer additions to the household (19/27 [70%]). Fight-eliciting triggers included owner attention, food, excitement, and found items. Some dogs had risk factors for behavior problems such as a history of living in multiple households (21/51 [41%]), adoption after 12 weeks of age (20/51 [39%]), or being acquired from a shelter (17/51 [33%]). Effective treatment recommendations included implementing a so-called nothing-in-life-is-free program, giving 1 dog priority access to resources, and administering psychotropic medication. Frequency and severity of fighting were significantly reduced after consultation. Owners reported a 69% overall improvement following treatment.
Conclusions and Clinical Relevance—Most treatment strategies were considered effective. Consistency and predictability of social interactions are essential in resolving interdog household aggression.