Mycoplasma hyopneumoniae as a causative agent of porcine enzootic pneumonia

Abstract

Mycoplasma hyopneumoniae is a very important pathogen which causes enzootic pneumonia (EP) affecting pig herds worldwide. M. hyopneumoniae establishes itself in the respiratory system causing pathological changes, and resultant pneumonic lesions can be detected at slaughter via lung examination, appearing as red to pink lesions which resolve over time, leaving scar tissue on the lobes. Mycoplasma spp. infection can be complicated by coinfections with other pathogens such as swine influenza virus (SIV) and porcine circovirus (PCV2). These coinfections result in worsening of clinical symptoms and lung lesions, therefore increasing the impact on performance of the affected animals. Therefore, it is important that focus is placed on improving overall respiratory health and managing overall herd health, rather than just solely focusing on M. hyopneumoniae. Management practices should be implemented to control the disease, which commonly involve vaccination to reduce the impacts of the disease. Effective vaccination is important, and can be ensured by correct vaccine handling, storage and administration. The vaccine used can also play a part in the success of the vaccination programme so this should also be assessed, which can be done via lung examination and noting of clinical signs and performance parameters. When vaccination is successful, the level of lung lesions should be reduced, performance improved and consistency between batches, demonstrating that respiratory health is more stable.