Future Dairy

Worm burdens

Worm burdens in animals at pasture are an inevitable fact of farming in Ireland. With calves and yearlings being turned out each Spring, farmers need a plan for pasture management and which should also include a worm control plan for the entire grazing season.

Important worms affecting cattle health in Ireland

The most significant stomach and gut worms (gastrointestinal) in cattle are Ostertagia and Cooperia. Lungworm, also known as Hoose pneumonia is caused by Dictyocaulus vivparaus. Lungworm problems during the grazing season are unpredictable as larval development and the risk of infection depend on turn out date, weather conditions and grass growth. Lungworm outbreaks can result in reduced weight gain of 37.4kg per animal1 as well as severe clinical disease, including death.

Seasonal spread of lungworm in 2015 & 20162

Late summer and early autumn are consistently the highest risk periods for clinical problems and death associated with lungworm infection in Ireland, according to the reports from Regional Veterinary Laboratories across the country. The graph below shows the seasonal spread of lungworm cases in Ireland with information from the All Island Animal Disease Surveillance Annual Reports.

Lungworm graph

Dairy heifer calves at biggest danger

Worms can have a huge effect on both the health and performance of all cattle, in particular first-season grazers and yearlings. Whether they are dairy heifer calves, who need to be putting on at least 750g/day to reach sufficient weight to be on target for breeding or beef calves to maximise production, they cannot afford to be pulled back by worm burdens.

''Worm burdens affect cattle thrive and suppress animal’s appetite which will inevitably affect their daily live weight gain.’’

Worm life cycle

The lifecycle of the important worms of cattle is around 3 weeks so cattle can have worm infections and potentially contaminate pastures with more eggs within a month of turnout. Infective worm burdens increase on pastures as the grazing season progresses. These worms will stop cattle from thriving and can cause disease and even deaths.

Cattle Worm Lifecycle

Clinical signs

Taking fresh dung samples and asking your local vet to do a faecal egg count is a good way of determining if animals need a dose or not. Hoose (lungworm) is the added complication in cattle. Unfortunately lung worm causes disease and death before they become adults and before they are detectable in dung. The best on farm test for lungworm are your own ears! If you hear cattle coughing while at grass in the summer or autumn, and if they have not been dosed recently with a persistent dosing product, it is quite likely they have lungworm and need to be dosed.

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    1Taylor et al. Vet Record (1997) 141, 593-597
    2All Island Animal Disease Surveillance Report 2015 & 2016