Mycoplasma bovis

In July 2017, MPI detected the bacterial infection Mycoplasma bovis in cattle in the South Island. Find out about this disease and what we're doing to try to control its spread.


Mycoplasma bovis is a bacterium that causes illness in cattle, including udder infection (mastitis), abortion, pneumonia, and arthritis. It does not infect humans and presents no food safety risk. There is no concern about consuming milk and milk products from affected cattle.

The disease was confirmed in July 2017 on 2 farms in a 16 farm dairy enterprise in South Canterbury. In August 2017 a third infected farm was confirmed in the Oamaru area. All 3 affected properties and the remaining 14 corporate farms in the group are under legal controls (a Restricted Place Notice) restricting the movement of stock and equipment off those farms to contain the disease. Mycoplasma bovis is common internationally and is present in most countries with animal production industries. It is not listed with the OIE (the world animal health organisation). It does not present a trade risk for New Zealand animal products.

This is the first time it has been found in New Zealand. The bacterium is an Unwanted Organism under the Biosecurity Act 1993.

Summary of Mycoplasma bovis – the diseases it causes, diagnosis and control [PDF, 119 KB]

No food safety risk

There is no food safety risk from eating New Zealand milk products or drinking New Zealand milk.

Containing and reducing its spread

MPI, animal production industry bodies, and veterinarians are working together on a large-scale biosecurity response to the disease. When a new, unwanted pest or disease is discovered in New Zealand, MPI has powers under the Biosecurity Act to contain it and minimise its spread.

To control the disease, we've issued 2 types of notices to farms that are affected. We've also issued the notices to farms that are suspected of being affected. To make sure the requirements of the notices are followed, MPI follows up all incidents of non-compliance.

Restricted Place Notices (RPNs)

All infected farms have been placed under Restricted Place Notices (RPNs), legally preventing the movement of animals, equipment, and risk materials from these properties.

MPI is tracing movements of animals and other risk goods on and off the properties to find out if other farms are at risk.

More information on Restricted Place Notices

Issued under section 130 of the Biosecurity Act 1993.

  • RPNs are issued to properties that have, or are suspected of having Mycoplasma bovis present.
  • The RPN prohibits all unauthorised movements of farm stock and other risk goods onto and off the property. This minimises the chance of the disease spreading from the property.
  • Any movement of cattle requires a permit from MPI.
  • Transport vehicles must follow a cleaning and disinfection process when they leave a restricted place.
  • Staff from AsureQuality (MPI's managing partner for biosecurity) are ensuring that cleaning, disinfecting, and permit requirements are complied with.

Notice of Direction (NoD)

Issued under section 122 of the Biosecurity Act 1993.

  • MPI issues NoDs to farms when an inspector or authorised person believes that movement of stock and other risk goods from a property poses a risk of spreading Mycoplasma bovis. For example, MPI may issue a NoD when animals from infected properties move to that property, but no testing has happened yet. We may also issue the NoD if test results are still pending.
  • The NoD aims to prevent further spread and doesn't restrict movement of stock or goods onto the farm.
  • Cattle can only move off the farm with a permit.
  • Other steps may be required (cleaning and disinfecting of vehicles).

Surveillance and testing

A large surveillance and testing operation is underway to build a picture of where the disease is and how it should be managed. MPI is checking the known infected farms, neighbours, and trace properties. MPI is also testing samples supplied through regional veterinary laboratories and Massey University. We're working with dairy companies to look at the milk from animals in the Waitaki and Waimate districts.

It is not known yet how or when Mycoplasma bovis entered New Zealand.

Presentation to farmers about the Mycloplasma bovis response operation [PDF, 853 KB]


Sampling and testing is a time-consuming process. MPI is carrying it out with urgency to limit the impact on the farming community as much as possible. 

We are also preparing for what might happen next. This involves preparing plans for the different possible scenarios (including eradication). When we're ready to make a decision, those plans will ensure it can be implemented smoothly and without delay.

Decision about eradication

We are aiming to eradicate Mycoplasma bovis. But before we can make decisions, we need to understand:

  • the extent of the disease – if it has spread
  • the scope of what we are dealing with.

We can't make long-term decisions that potentially have huge impacts on people without that knowledge. We need to be confident the disease is limited to the farms where we have detected it.

Our robust surveillance and sampling and testing programmes are helping us build this picture.

Once we know where it is in our national herd, we can decide:

  • how it can be managed
  • if eradication is possible.

MPI expects to achieve sufficient confidence to support a decision to eradicate if:

  • samples continue to test negative for Mycoplasma bovis
  • the evidence is pointing to the infection being contained to the current properties and not having spread wider.

We hope to have a clear picture by October. We will be very open about the status of the response and whether eradication will be possible or not. 

What you can do

Farmers should look out for:

  • unusual mastitis in cattle that doesn't respond to treatment
  • arthritis in cows and calves
  • late-term abortion
  • pneumonia in calves.

Not all infected animals get sick, but they can pass on the disease to other animals.  Mycoplasma bovis spreads between animals through close contact.

Farmers who see these signs in their stock should contact their veterinarian in the first instance or MPI on 0800 80 99 66.

Mycoplasma bovis mainly affects cattle and has little effect on other production animals. It does not affect horses and pet animals.


Beef + Lamb NZ resources

Who to contact

If you have questions about Mycoplasma bovis:

Last reviewed: | Has this been useful? Give us your feedback