Shaping the future of animal health

Dog & cat worms in humans

Worms in humans

Some parasitic life stages from intestinal worms of dogs and cats may also infect humans, if given the chance. When humans are infected by these parasites, the condition is referred to as a "parasitic zoonosis".

Hookworm larvae

Hookworm larvae can infect humans when the larvae pass through the skin often of the soles of the feet. This skin penetration usually causes inflammation which is very itchy and uncomfortable. The immature hookworm does not reach the intestine in humans.


Roundworm infection in animals can pose a serious threat to humans. In humans infection typically results from the ingestion of eggs on unwashed hands. These eggs are usually ‘picked up’ when patting infected animals (usually puppies or kittens) or through eating soil that is contaminated with roundworm eggs. Following ingestion, the immature roundworm hatches and then migrates around the body (‘visceral larva migrans’), eventually lodging in an organ or tissue.

Roundworm may be fatal if they migrate to the brain or they may cause impaired vision or blindness if they reach the eye.


Whipworm eggs, when ingested, can also infect humans. Once ingested, these worms develop in the intestinal tract where they may cause mild enteritis.


Hydatid tapeworm infection in dogs can lead to fatal disease in humans. When the eggs of the hydatid tapeworm are passed in the faeces of dogs, they may be consumed by sheep and various other species including humans (e.g. unwashed vegetables, hands).

These eggs eventually develop into hydatid cysts within body structures including muscles and organs. The cyst that develops may continue to grow and become a mass that can interfere with the normal function of neighbouring tissues or organs simply through pressure.

The hydatid tapeworm is common in many parts of Australia, however strict regulations are in place to try to control this parasite and its spread. Sheep dogs are not allowed to eat uncooked meat or offal from sheep and it is required that they are treated regularly with a suitable anti-parasitic drug (praziquantel) on a monthly basis.

The flea tapeworm does not pose a significant threat to human health, but can be passed on to humans through ingestion of infected fleas.