Echinococcus multilocularis in Ontario

Signs

The signs tend to occur in the late phase of the infection when large portions of the liver are infiltrated by the parasite. Signs may include:

• Enlarged abdomen

• Weight loss

• Lethargy

• Vomiting

 

 

Transmission

Dogs become infected with alveolar hydatid cysts by primarily eating large numbers of eggs of Echinococcus multilocularis. This most likely occurs by consumption of wild fox or coyote feces. It can also occur in association with an intestinal infection. 

 

 

Prevention

• Be aware of what your dog is eating

• Avoid contact with wild foxes and coyotes

 

 

Diagnosis

Testing is typically considered if signs consistent with alveolar echinococcosis are present and the dog is from a high-risk area.

Diagnostic imaging techniques [e.g. Ultrasonography (Ultrasound), Computed Tomography (CT) scan, and Magnetic Resonance Imaging (MRI)] are used to visualize the parasitic mass in the liver and to determine if surgery is an option. Histopathology and molecular testing of liver tissue are used to confirm the infection.

Blood tests may be used to confirm the infection but they are not available in North America at this time. 

 

 

Treatment

Treatment options for alveolar echinococcosis in dogs depend on the time of diagnosis.
Complete surgical resection is often possible in cases that are diagnosed in the early stages. Often, however, cases are diagnosed late and not all of the parasitic mass can be removed.  Such dogs will require chemotherapy for life.

For chemotherapy, albendazole (antiparasitic drug) is given daily for life. Typically, treatment with this drug slows down the growth of the parasite, allowing for the dog’s immune system to eliminate the infection.

Since some dogs with alveolar echinococcosis also have intestinal infections, treatment with praziquantel is recommended at the time of diagnosis. It is important to note that praziquantel is not effective against the liver infection (alveolar echinococcosis).