Owner-Directed Canine Aggression in Thailand: Triggers, Associated Factors and Clinical Interventions

Dog ownership provides physical and psychological benefits; however, inappropriate handling may lead to behavioural problems, particularly owner-directed aggression, which can compromise human wellbeing. This study investigated factors associated with owner-directed aggression and evaluated the effectiveness of interventions in Thailand. A randomised, single-blind clinical trial was conducted in 80 dogs exhibiting moderate to severe owner-directed aggression (including a history of biting). Aggression was assessed using owner questionnaires and veterinary interviews. Dogs were allocated to four groups: feeding toy (TOY), fluoxetine (DRUG), combination therapy (DRUG + TOY) and control. All groups received behavioural modification guidance. Aggression scores were measured before and after four weeks using a standardised scale. Multivariable analysis indicated that human-dog interactions and management practices were significantly associated with aggression scores, whereas owner and dog demographic factors were not. Baseline aggression did not differ among groups (p ≥ 0.05). Following treatment, all groups showed significant improvement (p < 0.05), with the DRUG and DRUG + TOY groups demonstrating greater reductions than the TOY and control groups. No significant differences were observed between DRUG and DRUG + TOY or between TOY and control. Mild side effects of fluoxetine, primarily drowsiness and reduced appetite, were observed during the first week and were less frequent in the combination group. Overall, fluoxetine (0.5-1 mg/kg) was more effective in reducing owner-directed aggression than environmental enrichment and owner education alone. However, enrichment and education play a crucial role in improving dog welfare and in sustainably reducing or preventing aggression and may enhance treatment outcomes when used alongside pharmacological intervention.