Adequate clean water access is a fundamental welfare requirement for pigs — failures in water provision cause rapid and severe welfare harm.
Water is the most fundamental nutritional requirement for pigs, and failures in water provision cause some of the most acute welfare emergencies in commercial pig farming. Even brief water restriction causes rapid behavioral distress, hyperthermia, and in severe cases death. The most common cause of inadequate water intake on farms is not absence of water but inadequate flow rates from nipple drinkers — pigs queue at drinkers, dominant animals monopolize access, and subordinate animals may be chronically under-watered in the same pen. Regular flow rate testing and provision of sufficient drinker points per pen are critical management practices. Salt poisoning following water restriction is a particularly severe welfare emergency that requires careful management of water restoration to prevent fatal brain edema.