Outbreaks of lungworm in cattle 'likely to occur' across UK in coming weeks

Increased threat of husk in adult cows and unprotected youngstock
Increased threat of husk in adult cows and unprotected youngstock

Outbreaks of husk (lungworm) in adult beef and dairy cattle, as well as youngstock, are likely to occur across the UK in the coming weeks and months.

Recent warm weather followed by rainfall have provided the perfect conditions for lungworm larvae to migrate from dung pats to grass.

Sudden outbreaks could be severe and, if the early signs of infection are not identified quickly, significant production losses could occur, including death in the worst cases, warns Merial Animal Health’s Veterinary Adviser Sioned Timothy.

Whilst youngstock are traditionally thought to be more susceptible to lungworm infection and associated respiratory disease, there is an increasing trend for adult cattle to be affected.

Immunity to lungworm is short-lived, and if natural boosting through low-level exposure to larvae does not occur, animals may be rendered susceptible to disease when the number of larvae present on the pasture increases.

However, even immune animals can succumb to disease in the face of high larval challenge.

Losses due to disease

Losses of up to £137 per animal can be attributed to lungworm infections and include additional costs and loss of income resulting from reduced milk production, disposal of dead animals, reduced fertility, laboratory diagnosis and treatment costs.

Even after recovery, lung damage can leave animals susceptible to secondary infections and affect long term productivity.

"The problem for farmers, and vets, is that lungworm can be difficult to diagnose at an early stage and may not be spotted until a full-blown outbreak occurs," says Ms Timothy.

"The initial signs of coughing can be confused with other respiratory diseases such as Infectious Bovine Rhinotracheitis (IBR), particularly in older cattle, but it’s important not to overlook the risk of lungworm in cattle of all ages as delays in treatment can hit productivity hard."

A rapid loss of condition and sudden milk drop in lactating animals are often observed during the acute stages of disease.

Animals have a deep harsh cough during activity which progresses to coughing at rest, with laboured breathing.

Severely affected cattle will typically stand with neck and head extended in the ‘air hunger’ position, and dairy cows may be observed resting more often and drinking and eating less than normal.

Farmers are advised not to wait until the whole herd is unwell, and should seek advice early in the course of disease to minimise the longer term impact.