The present study investigates the paradox of modern knowledge abundance and the simultaneous decline in canine welfare. Despite unprecedented access to information, millions of dogs worldwide face chronic under-stimulation, nutritional deficits, and subsequent behavioural disturbances. Based on a seven-year field study involving several hundred dogs, we identify boredom as the central driver of behavioural problems. Chronic under-stimulation initiates a predictable neurobiological cascade: reduced dopamine receptor sensitivity, increased frustration, lowered behavioural thresholds, and eventual aggression. This boredom–frustration–aggression pipeline reframes aggression not as an inherent defect but as a symptom of unmet fundamental needs. Nutritional analyses of commercial dog food further revealed systemic deficiencies: protein sources often biologically unavailable, carbohydrates of negligible metabolic value, and misleading labelling practices that obscure true dietary quality. These factors combine with unrealistic “quick-fix” training programmes, which promise behavioural solutions without addressing underlying welfare deficits. Our findings demonstrate that behavioural problems leading to shelter abandonment are rarely intrinsic traits. Instead, they represent adaptive responses to deprivation. The study highlights the urgent need for a holistic framework of canine care—integrating physical activity, mental enrichment, transparent nutrition, and welfare-based training. This research contributes to the growing body of evidence that aggression in dogs is largely misdiagnosed and mistreated. Recognising boredom as the primary welfare deficit offers a foundation for more ethical, effective, and compassionate approaches to canine behaviour and ownership.