With a wet summer forecast and cattle prices surging, one of the challenges for farmers across Australia is the rise of the bacterial disease pinkeye.
Subscribe now for unlimited access.
$0/
(min cost $0)
or signup to continue reading
Pinkeye, or infectious bovine kerato-conjunctivitis (IBK) is a highly contagious disease which can spread rapidly through a herd and in some cases cause blindness. It affects cattle weight drastically, with unwell stock losing high percentages of condition. In untreated cases cattle may struggle to find suitable amounts of feed.
It is also very painful.
Dr Jane Morrison, technical advisor at Coopers Animal Health says the disease is a big seasonal problem across Australia, and cattle producers need to vaccinate early against pinkeye.
"Pinkeye prevalence in Victoria is expected to be high this season," Dr Morrison told The Courier.
"This is due to the predicted seasonal conditions which will provide warmth and moisture, ideal for fly development and activation of the pinkeye bacteria."
Pinkeye is caused by the bacterium Moraxella bovis which infects the eye and produces a toxin. The toxin attacks the surface of the eye, eroding the surface and causing severe inflammation. Flies spread the disease through mobs of cattle.
"It causes a painful lesion, initially just with a weeping painful eye, says Dr Morrison.
"It progresses to where you get quite a significant infection in and around the eye, which causes a lot of discomfort to the animals, particularly when they're exposed to sunlight. Some of them will self-heal, and the animal will end up just with a small scar on the eye; and some of the animals will end up blind in that affected eye.
"Damage from long grass or thistles, dust, anything that irritates the eye, can allow that bacteria to start causing a disease. So it is quite widespread and it is also quite seasonal, generally spring through autumn. And that can vary depending on exactly where the property is located when the biggest challenge period is.
"There can be years where they get lots of pinkeye and years where they don't get very much pinkeye or, or have almost no pinkeye. And that very much relates to these other factors that are involved in why the bacteria suddenly causes disease."
Mallee grazier and Victorian Farmers' Federation livestock president Leonard Vallance told The Courier he was being swarmed by flies as he spoke.
"They're laid on pretty thick this year," Mr Vallance said.
"Look pinkeye is a problem every year, and the bug is in the paddocks up here. Having said that, this season the grass is pretty high, that's a problem.
"Our herd has immunity, but any animal, any bull for example, you bring in is bound to get it. The trick is vaccination; any animal coming onto the property gets a shot. I think that's a given: all cattle should be vaccinated."
Aside from the pain and potential injury of the disease, Mr Vallance says a blind or partially-blind beast is a danger to farmers and anyone else handling it.
"If a blind animal turned up at the livestock exchange, I think the Department of Agriculture would have something to say about it," Mr Vallance said.
"A good stock and station agent will make sure any animal with those problems is delivered directly to slaughter, but ideally it shouldn't be happening, if a farmer is doing his job properly. There are plenty of preventative vaccinations which have been around for years and do a good job."
Dr Morrison says while rainfall itself doesn't contribute to pinkeye, it creates the conditions for flies to multiply. The Moraxella attaches to the flies which begin carrying the bacteria from animal to animal.
"The other thing that a good season of rain does is make the grass grow. You have a lot of tall standing grass going to seed so the cattle, particularly calves, are walking through that," she said.
"That's bashing on their eyes and causing damage. So you've got a double whammy: when you've got rain, you've got lots of flies and you've got tall grass and in some situations you'll have tall thistles as a result of the rain - so you've got eye damage with the flies around, and that causes the problem."
While pinkeye and fly control products such as Piliguard and Easy Dose have been on the market for many years, Dr Morrison says the industry today is more aware of what contributes to pinkeye outbreaks and how better to reduce its incidence.
"It's a disease that has many factors: it has the bacteria, which actually causes the disease, but it won't cause the disease unless there's some environmental or animal factors relating to poor immunity and the age of the animals that help contribute," Dr Morrison said.
"When you're trying to prevent pinkeye, you need to think about all of those things. So the vaccination acts on the bacteria, but you still got to think about what else is happening to the animals and how much eye damage they're getting, and how many how much fly challenge they have. That's where fly control treatments come in as well. And managing pasture grazing to try and avoid eye damage."
One of the drawbacks of pinkeye, Dr Morrison says, is cattle will be rejected from feedlots if they show signs of eyeball scarring from the disease - even if they have recovered. She says limiting pinkeye means cattle producers will protect their income, both in terms of weights and markets.