Due to a unique feature of intestinal worm life cycles, puppies and kittens almost always are infested with worms.
Intestinal worms (called roundworms) frequently reside as dormant larvae in adult cats and dogs. These larvae become active when a female becomes pregnant. The larvae migrate from the adult to the juveniles, either through the uterus and placenta (in dogs), or through mother’s milk (in both dogs and cats).
Therefore, it is safe to assume that virtually all puppies and kittens are infested with worms by the time they are a few weeks old. What’s more, some types of intestinal worms can spread from pets to people. The worms can cause serious illness in human beings.
The Companion Animal Parasite Council (CAPC), a group of animal parasite experts, recommends de-worming puppies and kittens every two weeks, beginning at two weeks of age for puppies and three weeks of age for kittens. Click here for the CAPC’s complete guidelines for roundworm removal in kittens and puppies (warning: the site contains technical language).
Eight-week-old kittens definitely are not too young to be de-wormed. Also, they need vaccines to prevent deadly diseases such as feline panleukopenia virus. I recommend that you take the litter to the vet as soon as possible for shots and de-worming.