WILD dogs and foxes rather than domestic canines are currently the biggest threat to the spread of hydatid disease in sheep and cattle, which researchers believe is costing some abattoirs about $450,000 annually in condemned and downgraded offal.
Early findings a from Charles Sturt University study is shinning a light on the impact of hydatid infections in livestock and the importance of developing a commercialised vaccine to combat it.
Research from School of Animal Veterinary Sciences senior research fellow Dr David Jenkins and his students identified the role of wildlife in spreading the disease.
Sheep and cattle suffering from hydatid will have fluid filled cysts on the liver or lungs containing the next generation of tapeworms.
If the cysts are eaten by a wild or domestic dog of fox, they too become infected with tapeworms and after six weeks eggs are passed with faeces onto pasture.
Those tapeworm eggs, which can lay dormant in pasture for at least one year, are then eaten by grazing livestock and hatch in their intestine causing hydatids infection.
Limited hydatid research by honours student Sarah Fotheringham identified “hairy findings” for the beef industry related to producers’ and processors’ financial losses associated with reduced carcass weights.
Now, PhD student Cara Wilson is furthering those studies to investigate the need of a commercial vaccination for cattle. She has a database of at least two million animals and will complete her findings by mid next year.
“We have mapped out where hydatid- infected cattle are coming from and I’ve got infected cattle coming from all areas in Queensland and New South Wales and the Northern Territory, some cattle from South Australia and some from Victoria,” she said.
“There is a higher prevalence of infection in areas associated with the Great Dividing Range and coastal areas and the next part of the study is to look at why they are becoming more commonly infected in these regions.”
The University of Melbourne developed a hydatid vaccine for sheep in the early 1990s and more recently tests in New Zealand showed a higher dosage was also effective in protecting cattle. But there is no commercial offering for Australian producers.
Dr Jenkins said with so many wildlife reservoirs in the country it was impossible to stop wildlife from spreading the eggs.
Therefore, producers would need to be provided the incentive to hinder the cycle.
“Livestock at highest risk of infection with hydatid disease are those on properties where there is a risk of contract with faeces of wild dogs,” he said.
“The most practical way of protecting livestock is through vaccination, if there was a product commercially available.
“We are very motivated but unless you can show the farmers that there is a direct economic loss due to the infection of the parasite they are probably not going to get particularly excited about using a vaccine.
“The problem is you don’t know your sheep or cattle are infected until they are killed and their insides come out. It is the abattoirs who are losing most of the money.
“But half a million dollars is still quite a lot of money, even by today’s standards, and abattoirs are on such tight margins, if we could stop those losses I think it would be a really good thing for both producers and processors.”
While sheep are the major hosts, Dr Jenkins said the current grazing patterns of cattle meant tapeworm management was just as important to beef producers.
“The reason we are seeing it (hydatids) more in cattle than sheep these days is because you can run cattle in the rougher bushy blocks and often those are associated with the Great Dividing Range and these are places wild dogs are running as well,” he said.
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