Epidemiology of Lungworm in Cattle

Parasitic bronchitis is often a problem in pastured dairy calves. Infections are more prevalent in wetter areas.

Pastured cattle

Disease is most prevalent in pastured dairy calves but is also seen in weaned beef calves. Usually immunity develops during the first grazing season which is boosted by subsequent exposures. Acute cases of disease may be seen in adult cattle exposed to very large numbers of infective larvae.

Environmental conditions

Rain can disperse larvae in contaminated faeces. The fungal spore of Philobolus assists in dispersing larvae. Warm, moist conditions keep infective larvae alive and encourage fungal growth. Conditions favouring pasture growth also favour the development of the infective larval stage L3, thus outbreaks peak in the late summer and early autumn. Outbreaks of disease are often seen when a wet season follows a dry season, as this creates a gap in the natural immunity of the cattle.

dairy calf

Lifecycle of lungworm

Read about the lifecycle of Dictyocaulus viviparus and how it is affected by environmental conditions