Roundworms (including Toxocara canis) and tapeworms are intestinal parasites which can be found in any dog although infection is easily treated. Worms may cause sickness and diarrhoea in young animals. Adult dogs may show no signs
of ill health but still need regular worming.
Human infection (toxocariasis) may occur if mature Toxocara (roundworm) eggs are swallowed, however, it is very rare for anyone to become ill as a result. About 1-2% of healthy adults in the UK already possess Toxocara antibodies which mean that they have been exposed to Toxocara eggs or larvae with no ill effects.
Children are more vulnerable to Toxocara infection because they might pick it up when playing on grassland where the faeces from dogs carrying worms have been deposited.
On the rare occasions when human disease does occur it usually causes only mild symptoms. In exceptional cases it can cause damage to the eye in young children.
The chances of developing toxocariasis are minimal. It is estimated that there are only about two new cases of disease due to Toxocara infection per one million people each year.
However, if every owner treated their dog with a worming preparation, and cleared up after their dog, toxocariasis would be virtually eradicated. Newly deposited faeces are not infectious.
