Tail docking of dairy cows was once widespread in some countries but is now banned or discouraged in most jurisdictions based on welfare evidence.
Tail docking causes acute pain during the procedure, chronic pain during healing, and permanent loss of an important functional appendage. Tails serve important welfare functions: fly repulsion in summer, social communication, and as a signal of physiological state. Docking removes these functions entirely. The failure of the practice to produce claimed hygiene benefits means that animal pain was inflicted for no demonstrated purpose. This represents a failure of evidence-based practice in animal agriculture. Countries that have moved to prevent tail docking have experienced no adverse outcomes, demonstrating that the procedure is entirely unnecessary. Tail docking should be recognised as an unjustifiable mutilation wherever it persists.