Enzootic Pneumonia

Enzootic pneumonia is a persistent respiratory ailment in pigs, attributed to Mycoplasma hyopneumoniae (M. hyopneumoniae), and bears significant relevance to the emergence of porcine respiratory disease syndrome. Prevalent not only in the United States but also across the globe, this affliction stands as the predominant respiratory disorder among swine. Despite proactive endeavors to manage its impact, enzootic pneumonia continues to exact substantial economic repercussions on the global swine industry.

Etiology

M. hyopneumoniae is a bacterium belonging to the family Mycoplasmataceae and the genus Mycoplasma. It has no cell wall, a small genome, and weak resistance to the external natural environment and physical and chemical factors. However, it often sticks to the cilia lining the airways, leading to the development of chronic bronchopneumonia.

Fig. 1 Schematic diagram of Mycoplasma hyopneumoniae existing in host cells after infecting pigs.¹

Cause and Effect

M. hyopneumoniae is introduced into pig farms mainly through the purchase of subclinically infected animals or, in a few cases, through close-range airborne transmission. Once in a herd, M. hyopneumoniae may be transmitted to piglets or between inmates through direct nose-to-nose contact with infected sows.

Enzootic pneumonia affects nursery and finishing pigs the most. Affected pigs experience chronic respiratory disease, characterized by coughing, decreased growth rates, reduced feed intake, and increased susceptibility to secondary bacterial infections. The compromised lung function due to the disease leads to reduced performance and efficiency, ultimately impacting the profitability of pig production.

Signs and Symptoms of Enzootic Pneumonia

The main clinical features of the disease are cough and asthma, which can be divided into three types acute, chronic, and recessive according to the course of the disease. Clinical symptoms appear after the disappearance of maternal antibodies, and their severity varies with factors such as pig age, immune status, and concurrent infections. Most of them are chronic, and the most typical symptoms are dry cough without sputum. After secondary infection with other bacteria (such as Pasteurella, etc.), the condition will become more serious, manifested as cough, phlegm, high fever, loss of appetite or exhaustion, dyspnea, and increased mortality.

Diagnosis of Enzootic Pneumonia

Accurate and timely diagnosis of enzootic pneumonia is critical for effective disease management. BioVenic helps customers develop multiple diagnostics to confirm the presence of M. hyopneumoniae and assess the severity of infection.

• Immunodiagnostics
  Immunological testing of individual pigs is of little value. Immunohistochemistry (IHC), ELISA, and other methods are usually used to detect M. hyopneumoniae antibodies in pig herds.
• Molecular Diagnostics
  PCR directly detects bacterial genetic material in pig respiratory tract samples, which can confirm the presence of M. hyopneumoniae earlier and more accurately.

Treatment of Enzootic Pneumonia

While antibiotics are a prevalent recourse for addressing respiratory illnesses in pigs, their effectiveness in treating enzootic pneumonia stemming from M. hyopneumoniae is notably constrained. This limitation arises from the intracellular nature of the bacteria, hindering antibiotics from achieving therapeutic concentrations within infected cells. Nevertheless, the utilization of antibiotics may be warranted to combat secondary bacterial infections.

Prevention and Control of Enzootic Pneumonia

Prevention and control of enzootic pneumonia require a comprehensive approach, focusing on key aspects such as biosecurity measures and vaccines. BioVenic is committed to formulating the most comprehensive prevention and control plan for customers, as shown below.

• Vaccinations
  Implementing a vaccination program for young pigs and ensuring regular boosters is crucial. This approach builds herd immunity and reduces the spread of M. hyopneumoniae. BioVeni provides effective vaccine development services aimed at reducing the severity of clinical symptoms and limiting transmission.
• Good Husbandry
  Provide excellent conditions for pig feeding, optimizing air quality, ventilation, temperature, and stocking density. Age segregation measures are also very important.
• Strict Biosecurity Measures
  Measures such as strict quarantine protocols for new introductions, controlled entry, and exit procedures, and regular disinfection of facilities and equipment help minimize the risk of disease introduction and transmission. BioVenic guides biosecurity protocols tailored to the specific needs of each farm.

Endemic pneumonia remains a huge obstacle to the pig industry. BioVenic works to combat the disease by developing more advanced diagnostics, enhancing vaccine effectiveness, and investigating alternative treatment pathways. If you require more information, we welcome your inquiries and encourage you to interact with us.

References

1. Raymond, B. B. A., et al. "Mycoplasma hyopneumoniae resides intracellularly within porcine epithelial cells." Scientific reports 8.1 (2018): 17697.