Lungworm can appear from early June and is commonly seen in unvaccinated calves and naïve adult cattle.
Infection with lungworm (Dictyocaulus viviparus) results in an immune-mediated pneumonia, of which the earliest sign is a cough after exercise. Later signs include a persistent cough, milk drop and death in severe cases.
Once infective larvae are ingested from pasture they migrate to and mature in the lungs. Adult worms begin producing eggs between 3-4 weeks later and can shed millions of larvae onto pasture, to continue the lifecycle. Climatic conditions play an important role in the development of the infective larvae on pasture. Warm, wet weather favours larvae development.
Detection is currently based on clinical signs, detection of larvae in faeces and antibodies in either blood or milk. Lungworm should be considered in grazed animals with a persistent cough or signs of pneumonia.
Please contact the practice if you suspect lungworm may be a problem in your herd.