Aggressive behaviour in dogs is almost always caused or exacerbated by poor welfare, inadequate socialisation, or inappropriate training. Understanding causes improves both dog and human welfare.
Aggressive dogs are welfare victims in most cases. Fear-based aggression in dogs that have been inadequately socialised, exposed to punishment, or traumatised by previous abuse causes chronic anxiety. The dog suffers; so do those around it. Punishment as a training response to aggression increases fear and escalates behaviour. Dogs euthanised for aggression - often a treatable condition - represent a welfare failure. Early intervention by qualified clinical animal behaviourists using positive reinforcement methods achieves significant welfare improvement for the dog and reduces risk to humans.