Hydatid Disease

How is it spread?

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Hydatid disease is spread via the faecal-oral route. 

• ​Hydatid eggs pass out in the faeces of infected dogs, dingos and foxes, contaminating pasture. 
  The hydatid eggs are eaten by a suitable host, such as grazing cattle, sheep, goats or pigs. These eggs can then develop into cysts in their internal organs (‘offal’), especially the liver, heart and lungs 
  
  
• On the Australian mainland, these cysts also occur in several wild animals including kangaroos and wallabies.
  
  
• Hydatid cysts contain large numbers of new tapeworm heads. 
  
  
• The hydatid cyst is eaten by a dog, dingo or fox.
  
  
• The juvenile tapeworms develop into adults who produce more egss, continuing the cycle of infection. 
  

Eggs from dog faeces may be transmitted through the inhalation of dust containing eggs or via flies. Wind and water can also cause the movement of eggs in the environment. These forms of transmission only occur in area with a high level of environmental contamination, so are very unlikely in Tasmania. 

Eggs ingested by human may also develop into cysts, as they do in livestock.

What are the signs an animal may be infected with hydatids?​

Livestock and dogs do not usually show signs of infection. Infected kangaroos and wallabies may show breathing issues, have poor body condition and slow movements. This makes them more susceptible to predation.

In the early 1960s hydatid disease was extremely common in sheep and rural dogs. A distrubing number of human cases were occurring. The Tasmanian Government started a control program to stop transmission of hydatid disease to humans. 

This program was based on treating infected dogs and denying dogs access to the offal of sheep, cattle, goats and pigs.

Hydatid disease in Tasmania affects mainly dogs, sheep and cattle. Unlike mainland Australia, Tasmania does not have dingoes. There is no known involvement of other native or feral animals. Tasmania is also considered to be free from the presence of foxes.

The program was extremely successful. The transmission of the disease to humans in Tasmania ceased the early 1970s. Hydatid disease control programs have not been attempted on mainland Australia due to the sheer number and distribution of wild dogs, dingos, foxes and other susceptible wildlife.

Legislated treatment options for offal

Freezing is the preferred method where offal is being treated in the home environment:

The Biosecurity Regulations 2022​ (Section 7) detail the requirement for commercial sterilisation or another approved cooking process. Strict conditions apply to record keeping for these treatments.

These laws help prevent hydatids from spreading in Tasmania. Penalties apply if untreated offal is fed to dogs.

Tasmania's provisional freedom from hydatid disease

Tasmania was declared provisionally free of hydatid disease in dogs and sheep in February 1996. This does not mean that hydatid disease has been eradicated from Tasmania. It indicates that we have reached a significant stage in the eradication process. The disease is now rare in Tasmania. 

To stay provisionally free, we must keep reducing the risk of hydatids by doing the following:

Can people contract hydatids from infected animals? 

Yes. Humans can become infected by accidentally swallowing hydatid eggs. Hydatid eggs are very small and sticky. They can easily be transferred from an infected dog to human hands, via the dog’s coat or contaminated items such as footwear. Hydatid infections in people have the potential to cause serious disease and can be fatal. If you have any concerns, please speak with your doctor. 

What happens if my stock animals are found to have hydatids?

Positive cases of hydatids in animals are investigated by Biosecurity Tasmania. The details surrounding the detection will be considered. If necessary, the infected flock or herd may be quarantined and progressively culled. 

Each year in Tasmania up to 400,000 sheep and 60,000 cattle are inspected in abattoirs. Any lesions suspicious for hydatid cysts are tested at the Animal Health Laboratory. This is part of Biosecurity Tasmania’s hydatid surveillance program. Mainland abattoirs also look for hydatid cysts in Tasmanian sheep and cattle. Any positive results are sent back to Biosecurity Tasmania​

Hydatid disease in animals is a notifiable disease. Suspected or confirmed cases of this disease must be reported immediately. This can be done by calling the Emergency Animal Disease Watch Hotline (1800 675 888) or via your veterinarian.
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Minimising the risk of entry​ 

1. A veterinary certificate (from a registered veterinarian) detailing effective treatment within 14 days of export to Tasmania, OR

2. A Statutory Declaration (made by the dog owner) indicating effective treatment within 14 days of export to Tasmania, OR

3. Evidence of effective treatment, such as the worming product packet.​
   

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Recommendations for hunters and farmers

1. ​Farmers should dispose of dead livestock as soon as possible and in a manner that prevents access by dogs and other animals. 

2. Working dogs or hunting dogs should be wormed for hydatids regularly. This is particularly important if they are being taken onto someone else’s property. 

3. Muzzling dogs during hunting is recommended to help reduce the likelihood of scavenging.

More information

Glossary of hydatid images