These eggs hatch into tiny worms that move from your pet's intestine to its liver and lungs, then back to the intestine where they mature. The adult roundworm lays eggs that are passed in your pet's stool to the soil. Left untreated, roundworms can cause a potbelly and diarrhea. Vomiting, a rough coat and poor growth are other signs. Heavy infections damage your dog's liver, lungs and brain.
Death is possible.
Hookworm Hookworms are tiny threadlike parasites that affect puppies and adult dogs. They are a particular problem in areas with warm, moist sandy soil. Dogs get hookworms by either swallowing young hook-worms or hookworms can penetrate your dogs skin. Usually through the foot. Painful skin sores can result.