Lungworm in cattle: treatment and control

Abstract

Treatment options for clinical parasitic bronchitis (PB) are largely based on anthelmintics, with supportive therapy including non-steroidal anti-inflammatories (NSAIDs) and antibiotics, when indicated. Macrocyclic lactones (MLs), benzimidazoles and levamisole are all effective against adult and larval lungworms, so the choice of product depends on other criteria, including duration of action and ease of administration, which can be important in dyspnoeic animals. Control of PB in youngstock can be accomplished through the use of anthelmintics in early-season strategies designed to limit pasture Dictyocaulus viviparus larval populations, but are not easy to implement in herds other than on autumn-calving dairy farms. Likewise, though vaccination provides predictable control of PB in youngstock, it is best suited to calves from autumn calving herds, however, it can also be used pre-turnout as a ‘booster’ in previously exposed, older cattle. Grazing management has a limited role to play in the control of PB both because of unreliability and because some of the recommendations run counter to recommended grassland management practices. Veterinary clinicians need to familiarise themselves with all possible options and outcomes for the control of PB and tailor their recommendations to the individual farm and farmer.