Roundworms are a common parasite in dogs, but can also infect children. Adult worms live in the small intestine of dogs after migrating through the liver and lungs. Eggs are passed in the stool and contaminate the environment – the eggs can survive for up to 2 years. The eggs are ingested by a dog to start the life cycle again. Puppies can be infected in the uterus and via the milk and contaminated stools. They are most likely to show clinical signs (cough, diarrhea, stunting, pot-belly, pale gums). All puppies should be assumed to be infected and treated every 2 weeks. Pregnant and nursing bitches are sources of infection and should be treated before and after whelping. All of the common wormers (Pyrantel, Panacur) are effective in treating roundworms. Re-infection is commonly a problem in high density populations.