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 generally 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 means 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 up infective eggs when playing 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 low. It is estimated that there are only about two new cases of disease due to Toxocara infection per million of the population 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.
Dogs are infected with tapeworms through the ingestion of infected raw meat (e.g. rabbits and other small animals) (Taenia spp) or from the ingestion of fleas during grooming (Dipylidium caninum).
Worming your Dog
Pregnant Bitches and Unweaned Pups
Puppies become infected with roundworms from their mother while in the uterus or through her milk. Pregnant bitches and bitches with young puppies should be wormed frequently.
We recommend that bitches should be wormed before mating, after the first 45 days of pregnancy and after giving birth. They should then be wormed with their pups at 2, 5 and 8 weeks and after weaning. It is also possible to worm the bitch daily from day 40 of pregnancy to 2 days after whelping. This will ensure that the pups have an absolutely minimal worm burden at birth.
It is very important to worm puppies. It is reasonable to assume that all puppies are infected with roundworms (Toxocara canis) and produce larger numbers of eggs. We recommend that puppies are wormed monthly between 2 and 6 months of age.
Adult dogs are relatively resistant to roundworms unless they are pregnant. They become infected with tapeworms through contact with fleas and via meat. They should be routinely wormed every 3 to 6 months.