22 Aug 2018
Lungworm, Husk, Hoose, Parasitic Bronchitis: there are many names for the disease caused by the nematode worm
Dictyocaulus viviparous. Infective larvae on pasture are ingested, migrate to the lungs and enter the main airways. The presence of large numbers of worms obstructing the airways causes the symptoms in affected cattle. The parasite’s lifecycle is similar to that of gut roundworms (see diagram) and most cases occur in late summer / autumn.
The most effective way to control D. viviparous is to vaccinate. Two doses a month apart are required, with the second dose two weeks before first turnout. Typically it is not necessary to administer annual boosters, as natural
exposure usually maintains immunity. Care with anthelmintic use is important and ‘pulse release’ wormers are preferable to ‘sustained release’, as these will help in the stimulation of immunity to both lungworm and gut roundworms. In some herds the vaccination can be delayed until the second grazing season to avoid disease in adults, but this must be discussed with your vet.