Infection with small numbers of Dictyocaulus viviparous causes mild clinical signs. The aim in lungworm control is to prevent the manifestation of clinical disease and subsequent economic losses.
A combination of vaccination and deworming is effective for the control of lungworm in cattle. Total eradication of the parasite is difficult.
|Herds which do not use any anthelmintic cover in their first season; or use dose and move or strategic administration of long-acting injectables or pour-ons||Administer a full course of vaccine prior to turnout. Do not turn out onto clean pasture but onto pasture where there is an opportunity for exposure to natural infection. For example, pasture grazed by adult cattle last season.|
|Herds using long-acting/continuous release anthelmintics (including fenbendazole slow release boluses) which give cover throughout the ENTIRE first grazing season.||Administer a full course of vaccine prior to turnout in the second season.|
|Herds using long-acting/continuous release anthelmintics (including fenbendazole slow release boluses), but where calves are to remain at pasture after expiry of the bolus or treatment regime.||Give a full course of vaccination prior to first season (with second dose at least two weeks before worming). In areas of high lungworm risk give single booster dose prior to turnout in second season.|
|Herds which use long-acting/continuous release anthelmintics in the first AND second season at grass.||Seriously review such a policy, for there|
is often little indication for disease
control and it can seriously compromise
lungworm immunity. If this is not
possible, consider a full course of vaccine
prior to entry into the milking herd.
|Herds in which replacements are only turned out in their second season.||Administer a full course of vaccine prior to turnout.|
Note that when choosing a worming strategy for use after vaccination, a product that allows ‘leakage’ or gaps in its cover is to be preferred.
This is because it allows natural challenge to boost the level of immunity already gained from the vaccine. Note, however, that pulsed wormers only permit challenge if worms happen to be prevalent during the gaps in their activity.
Dosing lungworm vaccine.
Lungworm eradication is difficult. The aim in control is to prevent clinical disease.