A survey of more than 780,000 cattle slaughtered in New South Wales between 2013 and 2015 revealed that 5.5 per cent were infected with hydatid disease. Hydatid disease results from accidental ingestion of eggs of the tiny “hydatid” tapeworm that infects domestic and wild canids.
According to Dr David Jenkins, who will discuss the impact of Hydatid disease at the Australian Veterinary Association’s Annual Conference this month, these figures represent a financial loss to the abattoir of more than $450,000 from disposal of offal not fit for human consumption.
“Other annual losses included $1,200,000 due to reduced body weight of animals infected with hydatids—an unrealised loss for farmers.
“These results suggest that there are important financial impacts in cattle production due to hydatid disease. A vaccine developed for sheep against the disease has been trialled with cattle but it will be sometime before this vaccine could become commercially available,” Dr Jenkins said.
Hydatid disease leads to fluid-filled cysts in the lungs and liver, and less commonly in the spleen and heart. The major source of infection in cattle is from worm eggs shed by wild dogs and foxes, not domestic dogs.
“Infection in rural domestic dogs is now uncommon as a result of the development of highly effective wormers for dogs and dry dog food.
“The disease was introduced into Australia during European settlement with infected sheep and dogs. Little was known about the disease back then and it became a public health issue causing the deaths and debilitation of many colonists.
“Today, there’s wide transmission of the disease between wild dogs and marsupials along the entire eastern side of Australia, particularly in high rainfall areas. Transmission to sheep via wildlife occurs on farms located next to national parks or state forests containing wild dogs that enter the farms and defecate on the pasture. The infection situation is widespread in cattle grazed in rougher bush-blocks where wild dogs are also present. This grazing practice exposes cattle to eggs which are ingested accidentally while grazing.
“Through identification of these high risk areas there may be a better chance of controlling the spread of hydatid disease.
“If the vaccine becomes a commercial reality, there’s a real possibility of eliminating hydatid disease in these high-risk areas, leading to increased profitability for cattle production.”
The Australian Veterinary Association Annual Conference will be held 22-27 May at the Adelaide Convention Centre.