Cattle-wasting disease Bovine Johne's could be on 400 or more Western Australian farms - ABC News
Hundreds of Western Australian cattle properties are at risk of having the wasting disease Bovine Johne's Disease (BJD) in their herds after testing revealed the disease's potential presence on a southern property for eight years.
Key points:
- Cattle-wasting Bovine Johne's Disease is identified on a property in the south of WA
- Until now, the cattle strain of the disease was not thought to be present in the state
- Hundreds of properties are at risk of having infected animals via significant stock movement
The state's agriculture department, the Department of Primary Industries and Regional Development (DPIRD) has since determined the disease could not be eradicated without significant economic harm to the state's cattle industry.
The cattle industry will consider deregulating WA's current statewide management approach of BJD over the coming weeks.
Johne's disease — pronounced yo-nees — is a chronic, incurable bacterial disease that causes progressive diarrhoea, weight loss, and eventually death.
It can be prevented through vaccination.
While the sheep strain of the disease, Ovine Johne's Disease (OJD), is endemic in the WA sheep flock, up until now the cattle strain was not thought to be present in WA.
It was last detected in 2012 on a Kimberley cattle station, which lead to a successful four-year control and testing program to eradicate the disease.
Lag makes eradication difficult
DPIRD chief veterinary officer Michelle Rodan said the disease had been found in a "home bred" animal which was eight years old, which meant the disease had potentially been on the infected property for eight or more years.
She said the department had not been able to identify the source of the infection.
Dr Rodan said DPIRD's analysis of a number of properties at risk of having infected animals via stock movement was "significant" and in the order of 480.
"You might have it (BJD) in a herd at under one per cent prevalence, so the majority of those properties would be okay and don't have the disease, but there will be several properties out there that do have it.
"The complexity is to actually find those properties, and you have to place the regulatory burden on all of them in case they have the disease.
"It's little bit like doing COVID tracing, but doing it with a four to eight year lag, and having people locked up for that period of time while you're trying to resolve it.
"Unfortunately eradication with a test that cannot detect it in an infected animal until late in its life means you're always chasing four to eight years behind the disease."
Deregulation welcomed by northern producers
WA currently operates under strict import conditions for the entry of cattle from other states with BJD, designed to try and prevent the disease from entering its herd.
Dr Rodan said if the industry agreed eradication was impossible, WA would likely move from state-based management to an individual property management system.
"A number of systems would function perfectly well with BJD, others would want to keep it out, so the level of risk would be at a property level which is how they operate in the eastern states," she said.
Removing border restrictions and managing risk at a property level has been welcomed by Kimberley Pilbara Cattlemen's Association chairman David Stoate.
"We finally may see some commonsense," he said.
Mr Stoate said state-based control had restricted access to genetics from outside of WA and had cost the northern beef industry "a lot" of money.
"It restricts access to [high quality] genetics from outside of WA, which in the north of the state generally means from Queensland," he said.
Mr Stoate said WA cattle were not currently receiving a premium for their BJD-free status.
"The market argument for maintaining regulation just doesn't hold any water," he said.
Badgingarra-based cattle producer Dale Park was an advocate for maintaining WA's strict border rules to keep BJD out of the state and did not believe they had cost the industry much money.
He said he was disappointed but not surprised the disease had been discovered.
"The border controls were really only just, there was still stock coming in and out."
Discovery only a matter of time
Esperance-based vet Enoch Bergman said he suspected BJD had been present in WA for many years.
"We've just been touching the edges in terms of our ability to survey for it. I've always believed BJD has existed in WA and has been here for quite some time," he said.
"I believe now that we have found BJD in WA we can get on with helping producers learn how to manage it at an individual herd level and start focussing on diseases of greater significance."
Dr Bergman said there had been no proven threat to human health through the consumption of cattle infected with BJD.
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