Mycoplasma bovis

The M. bovis Eradication Programme

The first case of M. bovis was found in New Zealand on a dairy farm near Oamaru in July 2017. In May 2018, a decision was made to try and eradicate this disease and a 10-year Mycoplasma bovis Eradication Programme was initiated, originally delivered under a Government Industry Agreement (GIA) Operational Agreement between DairyNZ, MPI and Beef + Lamb New Zealand.

OSPRI took over surveillance operations for the M. bovis Programme on 1 November 2023, and assumed full management of the Programme under a National Pest Management Plan (NPMP) on 1 January 2025.

For dairy farmers, a new reduced National Pest Management Plan (NPMP) levy will finance the remaining programme.

Visit the OSPRI Mycoplasma bovis info hub for the latest updates and information.

Reduce the risk of introducing M. bovis

• Avoid direct animal contact with cattle outside your herd.
• Before you move stock, ensure you complete NAIT records and check the biosecurity health status of grazing properties.
• Purchasing new stock? Read the Pre-purchase Checklist.
• Secure boundary fences and better still, double fence at least two metres apart to stop nose-to-nose contact with neighbouring stock.
• Infected raw milk is the highest risk pathway for M.Bovis transmission to calves. Read more about options for safely feeding milk to calves.
• Traceability of raw milk is now a requirement under the new legislation. Ensure any milk you sell or purchase is recorded. See the OSPRI website on raw milk traceability for more information, including a record of raw milk movement template.

How M. bovis affects dairy cattle

• Untreatable mastitis.
• Severe pneumonia in up to 30% of infected calves, starting as a hacking cough.
• Ear infections in calves, the first sign typically being one droopy ear, progressing to ear discharge and in some cases a head tilt.
• Abortions, early calves, or small calves.
• Swollen joints and lameness (severe arthritis/synovitis) in all ages of cattle.

Know the signs and symptoms to look out for (PDF)

If your stock shows unusual levels of mastitis, abortions or present with arthritis or pneumonia, contact your vet immediately.

Protect your calves

• Calves can contract M. bovis through direct contact with infected cattle, or by consuming milk from infected cows.
• Low risk milk choices are calf milk replacer powder, acidified milk, or pasteurised milk. Read more about feeding milk to calves.
• Purchase calves from as few sources as possible.
• Deal directly with the source farm or via an agent.
• Avoid buying from saleyards because of the cattle mixing that occurs there.
• Ask about any M. bovis history available for the farm.
• Ask about cow and calf health on the farm over the past two seasons and use the Pre-Purchase Checklist.
• Ensure all stock movement records are up to date and recorded in NAIT.
• Only purchase calves with NAIT tags and record all movements within 48 hours.
• Ask your transporter to avoid mixing calves with other cattle in holding yards or on the truck.
• Keep purchased calves isolated from your main group for seven days and monitor them for signs of disease.

Getting support

As of 1 July 2025 the DairyNZ and Beef + Lamb NZ Compensation Assistance Team (DBCAT) service is no longer operational, and all further compensation claim queries must now be directed to MPI. You can find contact details and relevant forms on OSPRI's M. bovis compensation website.

If you or someone you know in the farming community is struggling, visit our wellbeing page for resources and emergency phone numbers.