Hydatids

• Hydatids are the cystic stage of the dog tapeworm Echinococcus granulosus.
• The tapeworm is tiny, only 3 - 6 mm long and lives in the intestines of dogs.
• Hydatids do not clinically affect cattle health but may be associated with production loss. A recent study found feedlot cattle with hydatids had carcases that were 7.2kg lighter than unaffected cattle. The other major loss from hydatids is at processing where meat products are downgraded due to the hydatid cysts.
• Hydatid cysts can be fatal in humans. Tapeworm cysts can be found in the liver or lungs (the two most common sites), the brain, kidneys, spleen, heart or other parts of the body. A heavily infested organ may fail, or a cyst may rupture and cause a life-threatening allergic reaction.
• Affected humans may be subject to complicated and prolonged surgery to remove cysts.

• The larval cyst forms in intermediate host animals such as cattle. Affected cattle organs are condemned at slaughter.

• Clinical signs in live cattle are rare, unless the cyst is in the brain, when the animal’s movement may be affected. At slaughter, affected organs are condemned and infected carcases may be trimmed or condemned.

• Cysts cannot be detected in live animals but are readily seen by examining the animal at the abattoir.
• Cysts can occur on the brain, heart, lungs or liver.

• There is no effective treatment for cattle with hydatid cysts.

• Monthly worming of working and pet dogs (with a product that contains the active ingredient praziquantel), as well as restricting them access to offal, will also help prevent hydatids.
• A cattle vaccine exists but is not registered in Australia. Vaccinated cattle tend to have fewer cysts than unvaccinated cattle but are still able to be infected. The effectiveness of the vaccine in reducing production loss is unknown.

Hydatids Factsheet

Animal Health Australia - Cattle health and biosecurity (general information)