Puppies and kittens are often born with worms. By three weeks of age, worms may be present in the intestine and will begin to lay eggs, which will then be passed in the stool.
The bitch or queen rearing her young may become re-infested from her litter.
Ingesting eggs passed in the stool transmits the worms. The fact that worms are not seen does not mean that the animal is worm free because usually only eggs are passed and they are invisible to the naked eye.
As the eggs take few weeks to develop prompt disposal of stool is advisable.
If children are taught basic hygiene when handling animals, and pets are dewormed reularly, the risk of human infection is virtually eliminated.
The drugs available only kill adult worms, so repeated dosing will eliminate the infestation as new adults emerge. Some drugs are not very effective. The staff will give advice on a good choice of dewormer.