Feedback from cattle farmers during the 2016 grazing season suggests lungworm disease outbreaks are becoming more prevalent and unpredictable.

An independent survey last year found that 40 per cent of 202 dairy farmers interviewed has heard cattle coughing at grass.

A third of milk producers said that they had had lungworm confirmed in their stock at some point over the last three years.

Half the disease outbreaks were reported in dairy youngstock during their first grazing season, but 40 per cent occuring in second season grazers.

According to MSD Animal Health veterinary adviser Paul Williams, planning lungworm control strategies for youngstock prior to their first grazing season makes sound financial sense.

Bovilis Huskvac is a live vaccine, made from irradiated larvae, which are incapable of causing disease.

For dairy calves, vaccination should be completed at least two weeks before the calves are turned out to grass, and for suckled calves it should finish two weeks before the calves begin to eat significant amounts of grass.

Paul Williams said: "“Lungworm infestation occurs as a result of infection with the worm Dictyocaulus viviparus.

"Cattle develop it after eating grass contaminated with infective larvae.

"Once in the gut, the larvae migrate through its wall to the lungs where they begin laying eggs after several weeks.

"A spell of mild, wet weather can create a sudden, dramatic increase in lungworm populations, which can be very harmful, even fatal, to any stock that have little or no immunity.

"That’s why vaccination is so critical,

“The vaccine produces a very good immune response against disease but it does not prevent all worms from natural infections completing their life cycle.

"This allows for the continued development of natural immunity, which often fails to occur where there is an over-reliance on wormers.”