Hookworms are intestinal parasites that infect dogs, cats, and humans. They are blood-suckers that in large numbers can cause significant anemia and protein loss. In people, hookworms are the cause of cutaneous larval migrans: an itchy, blistering rash where the larvae migrate under the skin on their way to the lungs and then the intestines. Children and immuno-compromised adults are very susceptible to infection. Hookworm eggs are passed in the feces, hatch into larvae in the soil, and infect new hosts who come into contact with the soil.
Litters of puppies and kittens are exposed to hookworms during nursing and while crawling around the feces-contaminated nest. The almost microscopic larvae migrate into the lungs, where they are coughed or gagged up to the mouth, and then swallowed. Once in the small intestine, the parasites reach adulthood, the stage at which they become blood-suckers. The adult worms are about a half of an inch long and are almost never detected in the stool. The mouth of the worm has sharp hook-shaped teeth that pierce the tissue and cause bleeding. Bloody diarrhea usually accompanies hookworm infection. Anemia results which causes lethargy and decreased immune function, leading to severe illness and sometimes death.
Hookworms are diagnosed by the veterinarian who performs a fecal flotation. Eggs passed in the stool are floated in a salt solution and observed under the microscope. Deworming will usually stop the diarrhea, but anemic and very dehydrated pets may require more aggressive treatment such as IV fluids, protein and electrolyte replacement, or even blood transfusion. Deworming medications are repeated at a three week interval because of the life-cycle of hookworms, to ensure that all the parasites are killed.
The stools from an infected pet should be removed from the environment to prevent re-infection and transmission to people. Hand washing is essential, and gloves are recommended when handling contaminated bedding, etc.