Dog aggression has multiple underlying causes and types. Understanding the cause enables welfare-appropriate treatment rather than punishment that worsens the underlying problem.
Dog aggression causes welfare harm to both the dog and the people or animals the dog targets. Fear-based aggressive dogs live in chronic anxiety, constantly vigilant for threatening stimuli. Pain-based aggressive dogs have typically received inadequate pain management and learned an appropriate but socially unacceptable response. Treating any aggression type with punishment compounds the welfare harm - punishment applied to a fearful dog increases fear, and punishment applied during pain increases pain association with handling. The welfare-centered response identifies the motivation underlying aggression, addresses it at the root level (reducing fear, managing pain), and uses counter-conditioning to build positive associations where threat associations exist.