Mud fever (pastern dermatitis) is a painful skin condition caused by prolonged wet and muddy conditions. Prevention through pasture and skin management reduces recurrent suffering.
Mud fever causes genuine pain through skin inflammation, bacterial invasion, and associated oedema. Affected legs become swollen and hot; horses show reluctance to bear weight in severe cases. The chronic form in heavy horse breeds — progressive lymphoedema — causes irreversible skin thickening and limb swelling that progressively worsens over years, causing significant long-term welfare harm. Prevention is far more effective than treatment: managing horse access to poached ground, drying and protecting legs after wet conditions, and providing hard-standing for horses in vulnerable periods addresses the primary cause. Owners who allow chronic mud exposure in susceptible horses are responsible for preventable welfare harm.