Ovine Johne’s disease (OJD) is an incurable wasting disease that can exist in some sheep flocks for years without obvious signs.

The disease is caused by Mycobacterium paratuberculosis, a bacterium that invades the lining of the gut wall and interferes with digestion.

The bacteria multiply in the gut wall and are shed in the dung.

The disease spreads when uninfected sheep consume grass or water that has been contaminated by infected animals.

This Primefact answers the following questions:

• When might I suspect that my flock has OJD?
• What should I do if I suspect OJD in my flock?
• How is infection confirmed?
• Should I just assume OJD and not bother with laboratory testing?
• If my flock tests negative, does that clear my property of OJD?
• What can I do to clear my flock once I know or suspect infection?