Tail docking in pigs is a mutilation performed to prevent tail biting, but root-cause approaches can reduce biting without requiring docking.
Tail docking itself causes acute pain and permanent sensory damage, while tail biting causes open wounds that lead to chronic pain and septicaemia. The EU legal position - that docking is prohibited unless tail biting risk cannot otherwise be managed - creates an obligation to address root causes before resorting to docking. Genuine implementation of this standard would significantly reduce suffering on both sides.