Warble (Hypoderma) infestation in Cattle: Biology, Clinical Signs and Control

Bovine hypodermosis, commonly known as cattle grub or warble fly infestation, is an important parasitic condition caused by the larvae of Hypoderma bovis and Hypoderma lineatum, belonging to the family Oestridae. The parasite has a complex life cycle in which adult female flies lay eggs on cattle hair, and the hatched larvae penetrate the skin and migrate through body tissues before reaching the back, where they form characteristic subcutaneous swellings known as warbles. Clinical signs include skin irritation, restlessness, firm swellings, breathing holes and discomfort, particularly in heavily infested animals. The infestation causes economic losses through hide damage, reduced productivity, weight loss and increased treatment expenses. Diagnosis primarily relies on clinical examination, identification of characteristic lesions and detection of larvae. Effective control involves regular inspection, careful larval removal, strategically timed veterinary treatment, appropriate insecticide application and herd-level management. Early detection and preventive measures are essential to minimise economic losses and maintain cattle health and productivity.