A South Canterbury dairy farm is in lockdown after a cattle disease made its way to New Zealand's shores.

But the Ministry for Primary Industries has confirmed the disease has only been found on the one farm.

Fourteen cows on the farm have tested positive for bacterial disease mycoplasma bovis, and are the first to have the disease in New Zealand.

A further 150 cows on the property have signs of infection.

Ministry for Primary Industries director of response, Geoff Gwyn, says they don't know how or when the disease entered the country, after confirming it on July 22.

MPI won't name the property or farmer involved.

Mr Gwyn said the disease poses no risk to humans or food safety and there is no concern about consuming milk products.

MPI has this affected property under legal controls, restricting the movement of stock and equipment off the farm, and is working with the farmer to contain the disease and treat the animals showing symptoms.

"Right now our strategy is to contain the disease and determine the size of the problem through surveillance and testing," Mr Gwyn said.

"Once we have defined the problem, we can then look at management options which could include area movement controls, selective culling of some stock or long term management measures."

What is mycoplasma bovis?
* A bacterial disease in cattle
* It can cause udder infection, abortion, pneumonia and arthritis
* Commonly found in cattle globally, including in Australia