What is Mycoplasma bovis?

Mycoplasma bovis is a bacterium that can cause a range of serious conditions in cattle and it's now in New Zealand. Find out more about the disease and how it spreads.

What is Mycoplasma bovis?

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

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

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

Mycoplasma bovis is not listed with the OIE (the World Organisation for Animal Health) and doesn't present a trade risk for New Zealand animal products. Internationally, the disease is managed by farmers through:

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

How is it spread?

On farm

Mycoplasma bovis is spread from animal to animal through close contact and bodily fluids, for example, mucus and 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 preventing the spread of stock off infected properties are the most appropriate measures to contain Mycoplasma bovis.

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

Vehicles pose very little 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 before leaving the property.

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 cattle, including dairy cows and beef cattle. It is common in many food-producing nations where infected animals that aren’t showing symptoms are processed for human consumption.

Who to contact

If you have questions about Mycoplasma bovis:

For support, contact your local Rural Support Trust:

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