Enzootic pneumonia and EP-like lesions

Enzootic pneumonia (EP) is the most common respiratory disease seen in pigs in the UK. However, the presence of EP-like lesions can also cause a significant decrease in production performance. Use this information to understand more about the disease.

Enzootic pneumonia (EP) is the most common respiratory disease seen in pigs in the UK. It is caused by Mycoplasma hyopneumoniae (M. hyo).

The pathogen is unique to pigs and present in more than 80% of pig herds in the UK at variable levels.

However, similar lesions can be caused by other infections and therefore not all will be true EP, hence ‘EP-like’.

Symptoms of EP include:

• Low-grade to severe cough
• Mild fever
• Slowed growth
• Secondary complications
• Consolidated lungs

EP may be spread by:

• Infected pigs entering the herd
• Droplet spread from coughing pigs on an infected farm
• Transfer of the disease from sow/gilt to her offspring on an infected farm
• Dust and fomites may also spread the disease. It has consistently been shown to have the ability to spread 3 km (2 miles) on the wind and, as such, any herd free of EP is vulnerable to infection from neighbouring farms as well as pigs passing on lorries
• People can carry the organism in the nose for 48 hours and are a potential source of infection.

It is important to understand the impact of EP on your herd and the economic implicatons for producers.

• EP has been shown to cause reductions in daily gain and feed conversion efficiency of up to 10%.
• EP has also been shown to predisposing pigs to other respiratory diseases.

The presence of EP-like lesions at slaughter can also have an impact.

• EP-like lesions are associated with a significant decrease in production performance, which can result in substantial economic implications for producers.
• Pigs with EP are likely to have a 1.26 kg reduction in post-trimming carcase weight, compared with those without.

There are a number of measures you can take to prevent EP in your herd.

• Buy stock from an appropriate source, depending on your herd health status
• Isolate incoming pigs for 6–8 weeks
• Optimise stocking levels and ventilation and ensure a thorough cleaning and disinfection programme is in place
• In heavily infected herds, it may be necessary to consider a partial or complete depopulation–repopulation strategy. This should be discussed with your vet.

Maintaining an EP-free herd

This guidance is only feasible in regions of low pig density, since EP can travel on the wind.

• Only buy EP-free stock and only buy from a reputable supplier. If possible, stock should come from the same source herd every time
• Isolate incoming pigs for 6–8 weeks (off site). During this period, check the status of the source herd to ensure it has remained EP-free. Pigs can be screened using a blood test before entering the main herd
• Alternatively, operate an all-in all-out policy, ideally by site, with thorough cleaning and disinfection between batches.

Effective control of endemic EP relies on an appropriate integrated management plan, based on the following principles:

• Environmental management that aims to reduce build-up of the organism and reduce chill stress on the animals
• Reduction of stress, which compromises pigs’ immune systems, providing an environment that allows mycoplasma to invade the respiratory tract
• Vaccination against mycoplasma. No vaccine can completely prevent EP but they can reduce lung lesions by up to 70%. Your vet can advise on the best strategy for your production system
• Strategic use of antibiotics
• Sign up to the Pig Health Scheme to monitor incidence of EP on your unit.

Management of the environment and stress is dependent on the design of the piggery and the facilities available. This will influence the success of any programme based on vaccination or the strategic use of antibiotics.

Make sure you work with your vet to develop a management plan that is appropriate for your farm.