A Pilot Study of the Primary Causative Agents of Pneumonia in Australian Sheep

Summary

A 2013 study by the National Sheep Health Monitoring Program indicated that up to 50% of Australian sheep flocks are diagnosed with a general form of pneumonia, which is a complex disease that can result in death.

This pilot study was conducted in abattoirs and investigated the primary types of bacteria that cause pneumonia in sheep produced in southern Australia.

Sheep lungs that had pneumonia lesions were sampled and 66% tested positive for just one type of bacterium (Mycoplasma ovipneumoniae). This suggests that this specific type of infection may be more widespread in sheep in south eastern Australia than previously thought.

Objectives

The main objective of the project was to analyse at least 200 lung and blood samples from five abattoirs. These samples were used to investigate the primary types of bacteria that cause pneumonia in sheep in southern Australia.

Key findings

• Of the lung samples collected from five abattoirs, 171 were tested and 113 (66%) were found positive for Mycoplasma ovipneumoniae.
• 100 blood samples were collected but have not yet been tested. They are stored at -20oC until appropriate test methods are available.
• The project developed culture and PCR methods that will enable more widespread, structured surveys of pneumonia infection and respiratory disease in Australian sheep.

Benefits to industry

The project was a pilot study and so did not produce any new information for producers and processors, however it did provide preliminary data to inform future research into pneumonia in sheep.

The preliminary information will also be used to update producers on the current state of the disease in their region.

MLA action

Due to the unexpected results of this project, MLA is planning to perform a more comprehensive survey of the occurrence of pneumonia in sheep in southern Australia.

Future research

Recommendations for future research include:

• surveys of pneumonia in Australian sheep (from abattoir samples) which cover:
  
  • all four seasons
  • geographical spread of abattoirs to provide regional data on pneumonia
  • information about sheep breed and age
• trials of a non-steroidal, anti-inflammatory drug in combination with antibiotics for pneumonia in sheep.