Five Facts about Lungworm Control in Cattle this Spring

Lungworm is becoming more prevalent in cattle herds

Cases of lungworm have increased, particularly in the north of England and Scotland. The disease is also becoming more common in adult cattle. This is as a result of cattle being turned out for longer which means cattle may not be protected for the later part of an extended grazing season¹. Secondly, farmers are being encouraged to more focus more on testing and diagnosis which is highlighting the presence of lungworm more often.²

Disease incident costs are enormous for lungworm in cattle

The overall cost of an incident of lungworm is conservatively estimated at £140 per adult cow in a herd. Decreases in milk production – estimated at 4 kg per cow per day, takes up 50 percent of the costs with the other half coming from laboratory fees, treatments, extra inseminations and the disposal of dead animals.³ 

Lungworm can also have knock-on effects on overall cow health and performance – potentially resulting in low fertility, lameness, mastitis and other secondary infections. It can also lead to long lasting production losses due to severe, irreversible lung damage.³

Coughing isn’t always the first clinical sign of lungworm disease in cattle

Clinical signs of lungworm in cattle include coughing and rapid breathing but these symptoms can take up to a fortnight to appear. Often the the first indicator of lungworm in adult cattle is production decreases, with milk production sometimes dropping almost overnight.³ 

Although it’s not common, sudden death can also occur. Cows who have suffered from lungworm several times before are most at risk to sudden death due to anaphylactic reactions.⁴

Your current worm control plan may need revisiting with your vet

Long lasting anthelmintics (preventative wormers) tend to be administered as a pour on or bolus to treat the whole herd prior to turnout. But this approach may not give first season grazers the low-level parasite exposure they need to build up immunity. 

Dairy farms are increasingly keeping young heifers inside right up until breeding, which means controlled nutritional input on the one hand, but also no exposure to pasture-based parasites on the other. 

Additionally, some long lasting anthelmintics can wear off before cattle leave contaminated pastures, which means a few animals still at grass can face a high worm burden later in the season and be vulnerable to infection.⁵

Vaccination is essential for effective long-term lungworm control

While preventative wormers have their place, they should be used sparingly on a case-by-case basis – and following faecal egg or larval counts, as well as body condition, weight and disease assessments.⁵ 

To manage the lungworm threat, producers should consider vaccinating first season grazers and naïve cattle alongside sound grazing management for more effective long-term control. 

Lungworm vaccination contains irradiated lungworm larvae that work their way to an animal’s lungs the same way normal lungworms would if ingested through grazing. As a result, vaccinated cattle may still develop the signature cough temporarily when the larva reach the lungs. However, because the larvae are irradiated, they can’t fully develop, which allows the animal to kill them off and develop enough immunity.

Effective lungworm control is best led by vaccination pre-turnout and sound grazing management, with anthelmintics only being used only as and when required.

When incorporating a vaccination programme for youngstock and adult cattle, there are a variety of issues to consider, so it is important farmers work with their vet at this time of year to develop an effective strategy.

Grazing plans are as essential for lungworm as they are for gut worms. Rotating paddocks, using silage aftermath, turning stock onto new leys to lower exposure and only grazing more infected pastures during low-risk periods (to gain a controlled level of exposure), are tactics that can all be considered in farm specific plans.⁶