Disease outbreak stops live sheep, goat exports

By ANNE BESTON and NZPA

Live exports of New Zealand sheep and goats to some countries have been stopped and farmers face the prospect of having to slaughter stock following a disease outbreak in Waikato and Canterbury.

Livestock movements on eight farms, seven in the Waikato region and one in South Canterbury, are under the control of the Ministry of Agriculture and Forestry following the mycoplasma disease outbreak.

Calves have been infected by the contagious goat disease in what is believed to be a world first.

Sixteen animals have died or been killed - six kids and 10 calves - from 34 cases of the organism in goat kids and 39 cases in calves in Waikato.

The ministry programme co-ordinator for exotic disease response, Dr Matthew Stone, said live exports of sheep and goats had been halted to international markets where the disease was unknown.

They included countries in Europe, South America and the Middle East.

The trade in live exports of sheep and goats has been relatively low over the past couple of years, with live goat exports worth about $2.8 million over the past year.

Because the organism - mycoplasma mycoides subspecies mycoides (large colony type) - has a similar name to a highly infectious cattle disease, trade officials are worried the unprecedented crossover from goats to dairy calves could be misunderstood by trading partners.

Wallaceville animal health research centre's molecular biologists are urgently sequencing the DNA of the Waikato disease to resolve questions over its identification and the failure of standard overseas screening tests to pick it up.

The disease causes polyarthritis or painful swelling of joints in livestock and can cause sporadic outbreaks of pneumonia, arthritis and mastitis in goats.

Dr Stone said the ministry wanted to find the "index" case where the disease first occurred, and work forwards to trace every potentially infected animal.

It was thought to have been spread to the calves after a Waikato dairy company unwittingly sold a tankerload of milk, including infected goat milk, to a big calf rearer.

Dr Stone said this raised questions about the practice of using unpasteurised milk off the farm to feed animals.

If a decision was made for an eradication programme, it was likely to be based on a test-and-slaughter system, where goat flocks or cattle herds would be restricted in movement until they tested clear of the organism, Dr Stone said.

Until now, New Zealand was considered free of the disease, although a single goat was reported to be infected in the 1970s.

The disease does not affect humans and the bacterium which causes it is killed by pasteurisation.