Other Parasites

Mosquitoes transmit heartworms, not pets. Humans are unnatural hosts for heartworms therefore cases of infection are rare. Many heartworm preventative medicines for pets do eliminate other parasites such as hookworms, whipworms and roundworms, which are more commonly seen in humans. Parasitic infections that can be transmitted from animals to humans are known as parasitic zoonoses.

In dogs, hookworm infection occurs through ingestion or skin penetration of hookworm larvae found in the stools or soil contaminated by feces of an infected animal. The larvae then develop and migrate to the intestines where they hook onto the intestinal wall and feast on the host's blood. The larvae of hookworms can penetrate the skin and infect humans through contact with soil or sand contaminated by feces of host dogs or cats. In a human host, the hookworm larvae do not migrate to the intestines and become blood-sucking adults as they do in pets. Instead, they move around under the skin and eventually die causing an inflammatory skin reaction known as cutaneous larva migrans, or "creeping eruptions." It is important to keep your pet free of hookworms with good hygiene, preventive medication and regular veterinary check ups. Also, keep stray dogs and cats out of sandboxes and gardening areas.

Roundworms are parasitic worms that are round in shape, live in the dog's intestines and consume partially digested food. Unlike hookworms, they do not attach to the intestinal wall, but literally swim in their food. Adult worms resemble spaghetti and may come out in the feces or vomit of an infected dog. Transmission to dogs is through eggs in feces, eating a prey animal that is a host (usually rodents), mother's milk, or in utero. In dogs, roundworms cause diarrhea, vomiting and in extreme cases pneumonia and intestinal obstruction.

In humans, roundworms can cause a serious condition known as visceral larva migrans. Most victims are children who are infected when putting contaminated fingers into their mouths. Once ingested, the roundworm larvae, though not in its usual host, tries to complete its lifecycle. The roundworm gets lost in the human body, usually in the eye, dies and generates an inflammatory reaction that can cause blindness. Proper hand washing can prevent infection.
Pet deworming of puppies and preventive medication will reduce environmental contamination.