Research on Pleurisy/Pneumonia in Sheep Achieves First Milestone

Our research project on pleurisy/pneumonia in sheep (Ovine Respiratory Complex, ORC) has achieved its first milestone.

After a slow start due to COVID-19 impacting travel, abattoir access and supply of laboratory consumables, the project is making progress.

We completed four abattoir visits between October and December 2020, inspected 6,587 carcases, and sampled 150 sets of lungs.

Polymerase Chain Reaction (PCR) tests for Mycoplasma ovipneumoniae, Mannheimia haemolytica, Pasteurella multocida, ovine Parainfluenza Virus 3 and ovine Respiratory Syncytial virus have been set up in our laboratory. Testing on samples from the 150 sets of lungs is now complete.

Sample collection and PCR testing are confirming the findings of our previous research on ORC, with widespread detection of M. ovipneumoniae in lungs from lamb and sheep carcases sourced from south eastern Australia.

M. ovipneumoniae has recently been identified as a primary pathogen of ORC in lambs. M. ovipneumoniae was first isolated from a sheep flock in Queensland in the 1960s that had shown poor growth rates and reduced exercise tolerance for some years. It has subsequently been found in most sheep raising countries internationally.

M. ovipneumoniae predisposes lambs to secondary lung infections with bacteria such as M. haemolytica and P. multocida. In this initial phase of our research, lower numbers of ovine lung samples have tested positive for M. haemolytica and P. multocida.

None of the sample tested to date have been positive for ovine Parainfluenza Virus 3 or ovine Respiratory Syncytial virus.