Mycoplasma bovis

In July 2017, the bacterial infection Mycoplasma bovis was found in cattle in the Oamaru area of the South Island. With the support of farmers, industry bodies and local communities, MPI is working hard to control the spread of the disease and, if possible, eradicate it from New Zealand.

On this page:

Situation report

The current number of 'active' Infected Properties (quarantined under movement restrictions) as at 9 March 2018 is 27.

The regional breakdown of total Infected Properties (IPs) from the start of the response is below. The number of 'active' IPs (some have since been depopulated, cleaned and had their restrictions lifted) is in brackets.

  • Canterbury – 2 (1 active)
  • Hawkes’ Bay (near Hastings) – 1
  • Mid-Canterbury (Ashburton) – 3
  • South Canterbury/North Otago – 11 (10 active)
  • Otago (Middlemarch) – 2
  • Southland (Winton, Lumsden, Invercargill, Gore) – 10

All infected properties are under quarantine controls set out in Restricted Place Notices under the Biosecurity Act. These legal controls restrict the movement of stock and equipment on and off those farms to contain the disease.

What is Mycoplasma bovis?

Mycoplasma bovis is a bacteria that can cause a range of quite serious conditions in cattle including mastitis that don’t respond to treatment - pneumonia, arthritis and late-term abortions.

The disease may lie dormant in an animal causing no disease at all but may, in times of stress, (for example, calving, drying-off, transporting, or being exposed to extreme weather) shed the bacteria in milk and nasal secretions. As a result, other animals may be infected and these may become ill or become carriers themselves.

It does not infect humans and presents no food safety risk. It is an animal welfare and productivity issue.

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

No food safety risk

Mycoplasma bovis is not a food safety risk. It is a disease that affects animal welfare and production. It affects only bovines, including dairy cows and beef cattle. It is common in many food-producing nations (like Australia, the United States, and in Europe). In these nations, infected animals that aren’t showing symptoms are processed for human consumption.

Cattle that are slaughtered as part of the Mycoplasma bovis response operation are processed. Before leaving the farm, they are assessed by veterinarians to confirm they are fit for transport. At the processing plants, MPI veterinarians assess the health of each animal before slaughter.

As with standard process, any animals that are sick, severely injured, or have any medication in their system are not processed for human consumption. This is a requirement of New Zealand law. All animals must also be examined after they’re slaughtered. This is to ensure the meat is safe and suitable for consumption.

How is it spread?

On farm: Mycoplasma bovis is spread from animal to animal through close contact and bodily fluids, for example, mucus and also milking equipment. Calves can be infected through drinking milk from infected cows. Urine and faeces are not regarded as significant transmitters of the disease, but the bacterium does survive for longer in a moist environment such as in piles of moist faeces or wet bedding material.

Off farm: The disease is mostly spread through movement of cattle from farm to farm. Movement restrictions on infected properties are therefore the most appropriate measures to contain this disease.

Farm equipment may play a role in the spread of the disease, especially equipment that comes into direct contact with infected animals such as AI instruments.

Vehicles pose a negligible biosecurity risk. It is absolutely safe for trucks to move from infected farms to other properties. All infected farms are under strict legal controls under the Biosecurity Act which require comprehensive cleaning and disinfection,

Mycoplasma bovis overseas

The disease is common internationally. Most other countries in the world, including developed countries in Europe, and the US, UK, Canada and Australia have Mycoplasma bovis in their normal cattle supply. In these nations, infected animals that aren’t showing symptoms are processed for human consumption (as is happening here where animals are culled from affected farms). Other countries successfully manage the disease through:

  • robust biosecurity practices on their farms
  • careful selection of replacement stock and breeding bulls
  • keeping their herds in a good state of health at all times.

Mycoplasma bovis is not listed with the OIE (the world animal health organisation) and does not present a trade risk for New Zealand animal products.

What farmers can do

Look out for signs of the disease:

  • unusual mastitis in cattle that doesn't respond to treatment
  • arthritis in cows and calves
  • late-term abortion
  • high numbers of calf deaths.

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

If you see these signs in your animals, contact your 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.

 Practice good on-farm biosecurity

Keep NAIT and other animal movement records up to date

NAIT is New Zealand’s cattle and deer tracing system and complying with it is law. From a biosecurity point of view, accurate record-keeping is vital to help track the spread of the disease and control it. It is also a useful tool for managing your own on-farm biosecurity by providing a complete history of brought-in animals. It is critical that you maintain up to date and accurate NAIT and animal movement records. 


Advice for farm service providers

Farmers should be using routine on-farm biosecurity practices to minimise risk to their animals. Service providers can help minimise risk by complying with the farm’s cleaning and disinfection requirements.

  • Don’t arrive unannounced. Let the farmer know you plan to visit their farm and ask their requirements.
  • Work with the farmer to comply with any farm biosecurity requirements.
  • Clean and disinfect footwear, protective clothing and equipment before coming on farm and again before leaving the farm.
  • Be proactive – assure farmers of your hygiene practices.

Advice for trucking companies

Trucking companies should work with farmers to meet their hygiene requirements.

All the properties under a Restricted Place Notice require permits to move animals between properties and to slaughter. The permits require the truck to be cleaned and disinfected at the end of each movement.

Is it safe for tradies/truckies to move from affected farms to my farm?

It is absolutely safe for tradies/truckies to move from infected farms to other properties.

All infected farms are under strict legal controls under the Biosecurity Act. These controls include a comprehensive cleaning and disinfection protocol which has been provided to them by the Ministry for Primary Industries (MPI). This protocol ensures that vehicles pose a negligible biosecurity risk.

All vehicles are being cleaned and disinfected on leaving the properties. Vehicles carrying animals – for example, transporters to the meat processing premises – are disinfecting on exit, going directly to the meat processor (not to other farms) and then being thoroughly cleaned and disinfected at the plant on completing the job.

Vehicles from neighbouring farms are not required to clean vehicles leaving their properties as the biosecurity risk is considered by MPI to be very small.

Minimising the risks at cattle shows and events

The risk of Mycoplasma bovis being spread at shows and events is relatively low. But until tracing is completed, it is still a potential risk. Our fact sheet has some simple precautions you can take to minimise the risks of Mycoplasma bovis being spread.

The biosecurity response - 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 and farms that are suspected of being affected. The notices – Restricted Place Notices and Notices of Direction – are to restrict the movement of any risk goods, including animals, out of these properties. To make sure the requirements of the notices are followed, MPI follows up all incidents of non-compliance.

Restricted Place Notices

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 RPNs

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).

Testing and surveillance

A large surveillance and testing operation is underway to build a picture of where the disease is and help us determine how it should be managed. MPI is testing animals on known infected farms, neighbouring farms, and trace properties (farms where animals or risk goods have been moved from infected properties, or which have supplied animals to infected properties). MPI is also testing samples supplied through regional veterinary laboratories from cows with mastitis. With the support of the dairy industry, MPI has tested milk from animals in the Waitaki and Waimate districts and is now extending that testing to samples from all farms across the country.

Mycoplasma bovis is a complicated disease to rule out and we need to have absolute confidence in all test results. We need to be able to give farmers and the New Zealand public certainty. This means test results can take time to analyse.

The samples we take can be either blood, milk, tissue or swabs. Each type of sample requires a different method of testing in the lab, adding to the complexity of the task at hand.

This is a tricky bacterium and while a positive result is a positive for the disease, a single negative result doesn’t mean a farm is in the clear. That is why we have to test multiple times over multiple weeks and months.

The tests we use

  1. The Polymerase Chain Reaction (PCR) test looks for Mycoplasma bovis DNA in the sample. It tells us if the animal is shedding Mycoplasma bovis in its milk or from its nose. It is very sensitive and can detect minute quantities of Mycoplasma bovis. We have been using these tests to look for Mycoplasma bovis in milk and swabs.
  2. Blood sample testing looks to see if the cow’s immune system is responding to M bovis. This tells us if the animal has been exposed to Mycoplasma bovis in the past.

The process takes up to 7 days from taking the sample on-farm, to getting a result. However, given the scale of the testing we need to carry out – we are prioritising the samples in terms of the risk. Infected farms are our priority, as well as farms that have either received animals from an infected farm or supplied animals to that farm (trace properties).

We have many people in the field who are collecting samples, and we thank farmers and vets and AsureQuality for their work.

MPI's laboratory - The National Animal Health Laboratory

Given Mycoplasma bovis is an unwanted organism in New Zealand – the testing cannot be carried out in any lab. It has to be done with a high level of security to ensure the disease is not spread through the testing process. Tests are carried out in MPI’s PC3 lab in Wellington – which has a high level of containment and security. 

Containment facilities that hold viruses and bacteria are approved according to an international scale called a physical containment, or PC, level. PC1 is the lowest containment level and is used for the safest bacteria and viruses, while PC4 is the highest.

New Zealand has many PC1 and PC2 labs, a handful of PC3 labs and 1 lab – the high-containment lab at Wallaceville – is an enhanced PC3 lab. This is because it contains more safety measures than a standard PC3. It's the highest level of biocontainment approved in New Zealand.

Culling animals to prevent further spread

In October 2017, MPI made the decision to remove and cull animals from affected properties in the Oamaru area to prevent further spread of the disease. We made this decision after doing tens of thousands of tests.

Around 5,000 cattle were culled with most of the cattle sent for slaughter, following standard practice. Mycoplasma bovis presents no food safety risk. The operation was completed at the end of December 2017.

All premises, transportation vehicles, and equipment involved in the de-population followed a strict decontamination and disinfection process to reduce any risk of the disease spreading.

Post-cull activity

A programme is now in place to decontaminate the affected farms and repopulate them. This process includes an initial clean-up and 2 rounds of disinfection with 14 days between rounds. Following this work, there will be a 60 day period where no cattle will be allowed on the farms (stand-down period). At the end of this 60 days we aim to get cattle back on the farms as quickly as possible.

Surveillance, monitoring, and testing will keep happening as a protection measure.

Industry support for de-population 

DairyNZ, Federated Farmers, and Beef+Lamb New Zealand support MPI’s decisions. They also recognise that this is a difficult time for the farmers involved.

The industry organisations believe that the measures are necessary to protect all New Zealand cattle farms from the disease. New Zealand is one of the few countries where Mycoplasma bovis is not found naturally. Because of this, the industry groups support measures to keep it that way.

Current hold on culling

MPI is currently deferring a decision on the need for further whole herd culling until a more thorough picture of the disease’s distribution in New Zealand is built. The nationwide dairy surveillance programme will help inform these decisions in future. Individual animals or small groups are still being culled for sampling purposes.

Pathways – how did it get to New Zealand?

It is not known yet how or when Mycoplasma bovis entered New Zealand. As part of the response, MPI has investigated possible means of introduction (known as pathways) to further inform decisions. We have investigated 7 pathways:

  1. Imported live cattle
  2. Imported frozen semen
  3. Imported embryos
  4. Imported veterinary medicines and biological products
  5. Imported feed
  6. Imported used farm equipment
  7. Other imported live animals 

We have completed a report into potential pathways. It has been reviewed by an international technical advisory group to ensure the analysis is as robust as possible. The report, along with the full report of the technical advisory group, will be released sometime in February 2018.

We have always said with this disease outbreak that it is unlikely we will be able to determine the exact pathway. We remain of that view – however, the report will give us good insight into pathway risk to support future management decisions.

Welfare support

MPI is working closely with industry organisations, the Rural Support Trust, and government agencies to support people who are most affected. We’ve prepared a fact sheet with information on looking after yourself if you’re affected by the Mycoplasma bovis outbreak.


Affected farmers can claim compensation where MPI’s exercise of legal powers (under the Biosecurity Act 1993) has caused them a verifiable loss, either:

  • as a result of damage to or destruction of the person's property, or
  • as a result of restrictions imposed on the movement or disposal of the person's goods.

Learn more about Biosecurity Act compensation
Mycoplasma Bovis compensation claim form – User guide [PDF, 446 KB]


2017 media releases

12 December    
15 November  8 November 12 October
2 October 8 September 29 August
23 August 11 August 7 August
4 August 1 August 31 July
28 July 27 July 25 July

DairyNZ resources

Beef + Lamb NZ resources

Who to contact

If you have questions about Mycoplasma bovis:

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