Ovine Johne's disease
Ovine Johne’s disease (OJD) is chronic wasting disease of sheep caused by the bacteria Mycobacterium paratuberculosis. The bacteria cause inflammation and thickening of the bowel wall, interfering with the normal absorption of food and resulting in severe weight loss, emaciation and eventually death.
OJD is a complex disease with a very long incubation period and it may take many years from the time of infection until the development of obvious signs of wasting.
Infected sheep shed the OJD bacteria in their dung contaminating pasture and water sources. The organism is very hardy and can survive in the environment for months of years. Lambs less than six months of age appear to be most susceptible to the infection, however due to the long incubation period obvious signs of illness are rarely seen in sheep less than 18 months of age.
OJD infection can result in significant financial costs to producers due to increased sheep deaths, decreased production and the trading restrictions that are placed on infected flocks and regions.
Download the following OJD publications:
Tips & Tools
Tips & Tools: On-farm management of ovine Johne's disease (PDF, 104KB)
This publication recommends a combination of annual lamb vaccination and careful grazing management for infected farms and takes readers through a five step process for managing infected flocks.
Fact sheets
The role of vaccination in the control of ovine Johne's disease (PDF, 311KB)
The role of grazing management in the control of ovine Johne's disease (PDF, 2.17MB)
Diagnosing ovine Johne's disease (PDF, 17KB)
The economic impact of OJD infection on sheep farms (PDF, 578KB)
Research and development report
Ovine Johne's Disease R&D Update 2005 December (PDF, 3.74MB)
OJD Harvest Year 2005 Proceedings (PDF, 1.5MB)
Ovine Johne’s Disease Research Report Abstracts March 2006 (PDF, 150 KB)
This publication includes abstracts from reports of the research and development undertaken in Australia as part of the National Ovine Johne’s Disease Control and Evaluation Program (NOJDP).
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