Echinococcus multilocularis is a parasitic tapeworm that primarily affects canines, particularly foxes and domestic dogs. It can cause a serious disease known as alveolar echinococcosis in humans, which occurs when a person accidentally ingests the eggs of the parasite. The eggs can be found in contaminated food, water, or soil. Once ingested, the eggs hatch in the intestines, releasing larvae that can form cysts in the liver and other organs. This condition can lead to severe health complications and requires medical treatment. Preventive measures include proper hygiene and avoiding contact with potentially contaminated environments.