The Human Risk
Roundworms and humans
The roundworm Toxocara canis can cause serious disease in humans. Humans can accidentally swallow the eggs of this parasite in a variety of ways. For example, eggs can remain in the soil and enter your house on your shoes or on wheels. Ingestion can also occur if your dog has groomed itself and then licks you, your hands or your face. Eggs need to be in the environment for a certain amount of time before they become infective. Often these infective eggs have been dispersed from the original poo and are all over the place!
If a human accidentally swallows an infective egg, it can move to the back of the eye and cause blindness. This is rare – but it does happen, and can affect both adults and children after swallowing worm eggs in the environment, for instance in a park.
Clearing up after your dog is the first step to reducing eggs in the environment, it is part of being a responsible dog owner and as we all know dog poo is just not something we want to step in as it is quite disgusting! However clearing up after your pet will not prevent every worm egg from being left behind, and therefore regular worming is required to reduce this number significantly.