External parasites including lice, flies, and mange mites cause significant but often underestimated welfare harm to cattle. Recognition and management are key welfare priorities on beef and dairy farms.
External parasites cause chronic welfare harm that is easily overlooked because affected animals adapt their behaviour rather than displaying obvious acute distress. Cattle with heavy lice burdens show persistent rubbing and restlessness; those under intense fly pressure spend less time grazing and more time defensive behaviours. Hypodermosis — warble fly infestation — causes intermittent episodes of acute pain as larvae migrate and create breathing holes through the skin. Mange causes progressive skin damage with intense irritation. The welfare burden is chronic and cumulative. Treatment at housing prevents winter build-up of lice; strategic fly control during the summer grazing period reduces fly-related stress. Regular body condition monitoring and coat inspection reveal parasite burdens that otherwise go undetected.