Hookworms and roundworms
Hookworms and roundworms (Ancylostoma and Ascaris ) are common nematodes of dogs and cats. When a human accidentally eats something contaminated with worm eggs from a pet’s stool, the eggs hatch in the intestines and begin migrating throughout that person’s body. Worm larva can also burrow through intact skin. Because these parasites were designed to live in dogs and cats, they become lost in the human body – often in the liver or eyes.
This disease occurs most often in children due to their poor hygienic practices. In the eye the larval nematodes cause inflammation and blindness. In the liver they can cause chills, malaise and an elevated white blood cell count. To prevent this disease, have your pet’s stool checked yearly for parasites and feed a monthly heartworm preventative that also kills nematodes. Many Heartworm preventative for dogs contain ingredients that keep your pet free of intestinal worms.
Roundworm infection can cause morbidity in humans, however many roundworm infections remain asymptomatic and therefore remain underdiagnosed and underappreciated.
Once inside a human, roundworms may migrate to areas of the body other than the intestine. This may make the disease more severe depending on the migration path and destination of the roundworms. When they migrate to the eye, they can impair vision or cause permanent blindness. These “wandering roundworms” can also damage the liver, heart and lungs in humans.
Hookworms are unique in their ability to penetrate human skin. When people come into contact with contaminated soil, infective larvae can pass through a person’s skin and begin a prolonged migration under the skin, causing a painful, itchy rash. Some species of hookworms can penetrate deeper tissues. In rare cases, hookworm larvae may migrate to the intestine, causing an inflammatory response.