Stomach Worm

The adults live in the stomach. Eggs are passed out in the manure, hatch and are picked up by fly maggots feeding in the manure. The worm larvae develop within the maggot and are then found in the mouth-parts of the fly. Horses become infected when they swallow the larvae that are released from the flies as they feed around the lips, nostrils and wounds of horses. Larvae deposited on sores and wounds do not complete their life cycle but cause intense irritation resulting in the wound failing to health, sometimes called summer sores.