A disease that has caused significant sheep losses in the past is being detected in less animals inspected as part of the National Sheep Health Monitoring Project (NSHMP).
Ovine Johne’s disease (OJD) is a serious wasting disease that affects mainly sheep, and to a lesser extent goats. It is caused by the sheep strain of the bacteria Mycobacterium paratuberculosis.
Data collected from the 1 to 1.5 million mutton sheep inspected every year as part of the NSHMP indicates that the level of OJD infection in Australian sheep flocks has declined. But as Animal Health Australia’s biosecurity manager Dr Rob Barwell warned, this is no reason to be complacent. While the big picture may look promising, there is always work to do in managing this disease.
“The data we have gathered over the past 10 years has shown us that infection levels in inspected sheep lines have demonstrated a downward trend in all states. However, there are some regions that have not shown the same level of decline which means we need to get the message out there to all sheep producers to improve their management practices to manage the disease on farm or avoid it coming onto their farms,” he said.
At this stage, the reduction in infection levels is being attributed to a strong take-up of the OJD vaccine (Gudair®), which is one of the tools available to help manage the disease. Dr Barwell advised producers to keep using the vaccine, even when they are not seeing cases on farm as it can re-emerge if stopped.
“It is important to remember that OJD usually enters a flock through the introduction of infected sheep or stray animals,” he said. “Sheep droppings and contaminated run-off can also spread the infection between farms once it has ‘seeded’ into an area, and the risk of spreading infection via natural waterways and floodplains is also present.”
All sheep producers are encouraged to download the FarmBiosecurity phone app so they can develop their own biosecurity plan, visit the sheep page on the Farm Biosecurity website for the Sheep Health Statement, or visit ojd.com.au to learn more about the disease.