Effects of clomipramine hydrochloride on dominance-related aggression in dogs

Objective-To compare effects of the serotonergic drug clomipramine hydrochl oride with those of placebo for treatment of dominance-related aggression i n dogs. Design-Randomized, placebo-controlled, double-blind clinical trial. Animals-28 neutered dogs > 1 year old with dominance-related aggression. Procedure-Dogs displaying greater than or equal to 3 aggressive episodes/wk toward greater than or equal to 1 human family member in response to ident ifiable behavioral triggers were included in the study. Owners were instruc ted not to change patterns of interaction with their dogs during the study. After 2 weeks of baseline observations, dogs were treated for 6 weeks with clomipramine (1.5 mg/kg [0.7 mg/lb] of body weight, q 12 h; n = 15) OF pla cebo (13). Responses to triggers were assigned the following aggression sco res: no response, 0; growl or lip curl, 1; snap or bite, 2. Mean scores for responses to triggers were obtained during the 2-week pretreatment period (baseline) and during the first and second weeks, third and fourth weeks, a nd fifth and sixth weeks of treatment. At the end of the study, owners assi gned a score designed to evaluate their overall perceived change in aggress iveness; this was referred to as the global score. Results-Mean aggression scores decreased at the fifth and sixth week of tre atment in both groups, compared with baseline scores. However, mean scores between groups were not different. Global scores, assigned by the owner, ge nerally reflected changes in mean aggression scores. Conclusions and Clinical Relevance-Compared with placebo, clomipramine admi nistered to dogs at the dosage recommended for treatment of separation anxi ety did not reduce aggressiveness toward human family members.