Mycoplasma bovis

In July 2017, MPI detected the bacterial infection Mycoplasma bovis in cattle at a South Canterbury dairy farm. 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 has been confirmed (July 2017) in 14 cows at a South Canterbury dairy farm and about 150 animals are showing clinical signs that may be the disease.

 The farm has controls in place restricting the movement of stock and equipment from the property 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).

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.

What MPI is doing

The affected farm has been placed under a Restricted Place Notice, legally preventing the movement of animals, equipment, and risk materials from the property.

Affected animals are being treated for their symptoms. MPI is tracing movements of animals on and off the property to find out if other properties are at risk.

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

MPI is working with the country's animal production industry bodies and veterinarians.

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

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.

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

Who to contact

If you have questions about Mycoplasma bovis:

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