Feline Hookworm Infection

Hookworms are parasites named for the hook-like mouth parts they use to attach to the intestinal wall. They are only about 1/8-inch long and so small in diameter that they are almost invisible to the naked eye. The scientific names for the most common feline hookworms are Ancylostoma tubaeforme and Ancylostoma brasiliense. In general, cats tend to harbor relatively few hookworms compared to the large numbers found in dogs.

Hookworms are more common in warm, moist environments. Overcrowding and poor sanitation can also contribute to infection. Most common in outdoor cats, however indoor cats can get potential infections when they’re born or from eating cockroaches.

Feline hookworms tend to “graze” along the lining of the small intestine and are considered “tissue feeders." When the parasites suck the cat's blood, an anti-coagulant substance is injected at the feeding site. This can cause the cat to suffer blood loss and intestinal distress, though anemia is a more significant problem in kittens than adult cats. Evidence of hookworm infection includes anemia due to blood loss, the presence of digested blood in the stool, a poor hair coat and weight loss.

A cat may become infected when he/she swallows hookworm larvae, or immature worms from stool or even from cockroaches who are infected with the hookworms. The larvae may also penetrate the skin and migrate to the intestine to mature and complete the life cycle. 

Hookworms are diagnosed with a microscopic examination of a small stool sample. The stool is mixed into a special solution that causes the eggs to float to the top. The eggs are then examined under a microscope and identified. There are also sensitive PCR tests that detect the hookworm DNA. Since there are so many eggs produced on a daily basis, hookworm infection is usually fairly easy to diagnose.

One adult female hookworm is reported to produce thousands of eggs a day, and therefore can lead to heavy environmental contamination in soil, dirt, or litter.

Fortunately, treatment is safe, simple and relatively inexpensive. There are several effective drugs that will kill hookworms. These can be given topically or orally and have few, if any, side effects. However, these drugs only kill the adult hookworms. Therefore, it is necessary to treat again in about two to four weeks to kill any newly-formed adult worms that were larvae at the time of the first treatment. Ideally, cats are treated for worms during their kitten vaccination series. In rare cases, hospitalization or a blood transfusion may be necessary for cats that experience severe anemia.

With appropriate diagnosis and treatment, the prognosis is good for full recovery from hookworm infection. Severely infected animals can potentially need more supportive care or medications to support them. 
 

Hookworm prevention should include the following measures:

Feline hookworms do not infect humans internally. However, the larvae can burrow into human skin, causing a disease called cutaneous larval migrans. Also known as “ground itch," this skin infection does not lead to maturation of the larvae. Because contact of human skin with moist, larvae-infected soil is required, infection rarely occurs when proper hygiene is practiced. Humans do have separate species that can infect them though with true intestinal infections.

Strict hygiene is especially important for children. Do not allow children to play in potentially contaminated environments. Be mindful of the risk posed by public parks and uncovered sandboxes. Sandboxes with fitted covers are recommended to prevent intestinal parasites in children.