Liver Tapeworm

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What causes liver tapeworm cysts?

This condition is caused by the larvae of the tapeworm Taenia hydatigena.

Lifecycle: The tapeworm needs two hosts: a carnivore ( eg. a wolf or dog) and a herbivore (e.g. caribou). The tapeworm grows and lays eggs in the intestines of the carnivore. Eggs come out in the carnivore’s droppings and contaminate plants that are eaten by the herbivore. The eggs hatch into larvae that travel to the herbivores liver where they form cysts. Carnivores become infected when they eat liver containing cysts.

Liver tapeworm cyst embedded in liver of a caribou. (inset is an isolated liver tapeworm cyst)

Where do liver tapeworm cysts occur?

The adult tapeworm occurs in the intestine of carnivores (wolves, lynx, dogs and cats) without causing any harm.

The larval stage of this tapeworm can occur in caribou, moose, wapiti (elk), Dall’s sheep, and white-tailed deer.

In the NWT and Nunavut, Taenia hydatigena occurs commonly in caribou and moose.

What are the signs of liver tapeworm cysts?

Animals will probably appear healthy.

In the herbivore host, the larvae form large cysts attached to the liver or the lining of the body cavity.

There also may be white, star-like scars on the surface of the liver.

How can I protect myself?

You cannot be infected by the cysts of T. hydatigena.

Cysts can easily be removed from the liver during butchering.

Can I eat the meat?

Meat from infected animals is suitable for human consumption.

Cooking will kill the parasite.

Dogs can be infected with tapeworms if they eat the liver cysts.

Do not feed infected parts to dogs.

Samples to collect

Cysts or affected liver tissue.