Feline Hookworm

What are hookworms?hookworm_infection-1

Hookworms are intestinal parasites of the cat and dog. Their name is derived from the hook-like mouthparts they use to anchor themselves to the lining of the intestinal wall. They are only about 1/8″ (two to three mm) long and so small in diameter that they are barely visible to the naked eye. Hookworms feed on the tissue fluids and blood of their host.

The scientific names for the most common feline hookworms are Ancylostoma tubaeforme andAncylostoma braziliense. Occasionally, cats will also become infected with the dog hookworm, Ancylostoma caninum.

In general, cats tend to harbor relatively few hookworms when compared to the large numbers found in dogs. Also, the feline hookworms tend to be less aggressive bloodsuckers than the canine species.

Are some cats more likely to get hookworms?

Hookworms are more common in warm, moist environments. Conditions of overcrowding and poor sanitation contribute to infection.

How do cats get hookworms?

hookworm_infection-2Female hookworms pass hundreds of microscopic eggs in the cat’s stool. The eggs are not visible to the naked eyeLarvae or immature hookworms will hatch from the eggs and persist in the soil for weeks or months. When a cat inadvertently swallows larvae, often by grooming its feet, a hookworm infection is established. The larvae may also burrow through the cat’s skin and migrate to the intestine, where they may mature and complete their life cycle. It takes approximately 2-3 weeks for an infective female larva to mature and produce eggs.

In dogs, prenatal infection (infection prior to birth) may be a significant problem. Puppies may become infected from placental blood from an infected mother, or after birth through her milk. Prenatal infection has not been demonstrated to occur in kittens, although kittens can be infected through their mother’s milk.

What are the clinical signs of feline hookworm infection?

Feline hookworms tend to “graze” along the lining of the small intestine, and are considered “tissue feeders.”. When they do suck blood, an anti-coagulant substance is injected at the feeding site. Therefore, the cat can suffer blood loss from the hookworm’s feeding as well as continued bleeding into the bowel from the hookworm’s attachment sites. The blood-loss anemia attributed to hookworms is a more significant problem in kittens than adult cats.

Evidence of hookworm infection includes anemia, the presence of digested blood in the stool, a poor hair coat, and weight loss.

Skin irritation and itching, especially of the paws, can be signs of a heavily infested environment, since the larvae burrow into and along the skin.

How is hookworm infection diagnosed?

To diagnose roundworm infection, a fecal ova and parasite screen will be run.  A small amount (~2grams) of fresh feces (not more than 24 hours old) is needed to run the test.   This sample will be sent to a reference lab which uses a testing process called centrifugal floatation with microscopic examination to look for parasite eggs . This is the most accurate way to get a diagnosis as simple fecal flotations may miss parasite eggs.  In some cases, it may take more than one test to find the parasite as they are not always shed in the fecal mater continuously.  The number of eggs does not necessarily correlate with the number of worms present. In fact, the number of eggs passed can be greater with light infections of smaller numbers of hookworms.

How is feline hookworm infection treated?

Fortunately, treatment is safe, simple, and relatively inexpensive. After administration of the deworming medication called an anthelmintic, the adult hookworms are killed. However, most anthelmintics do not kill the larval stages. Therefore, at least two treatments are needed, given at two to three week intervals, to kill adults that matured after the previous treatment. Ideally, kittens are treated for intestinal worms starting at 2 weeks of age.

Will my cat recover?

With appropriate diagnosis and treatment, the prognosis is good for full recovery from hookworm infection. In rare cases, kittens or debilitated cats might require a blood transfusion because of severe anemia. These patients have a poorer prognosis and extensive treatments are usually necessary.

Can hookworms be prevented?hookworm_infection-3

Prevention of hookworm infection should include the following measures:

  • Kittens should be appropriately dewormed as recommended by your veterinarian. The first deworming should be given at two to three weeks of age. Note that this is prior to the time most kittens are seen for first vaccines. It is entirely appropriate to present new kittens for initial examination and deworming only. Deworming is continued every 2 weeks for kittens until they are 12 weeks old, then monthly until 6 months of age.
  • Prompt treatment for worms should be given when any parasites are detected;It is appropriate to routinely deworm all adult cats. Routine deoworming interval will depend on risk, but minimum recommendation is 2-4 times yearly.   It is also advisable for all cats to have a fecal examination once to several times a yearly depending on their risk.  This way we can make sure our dewoming programs are working and also pick up other parasites not currently being treated for.
  • Use of a monthly heartworm preventive that also prevents hookworm infection is highly recommended.
  • Appropriate disposal of cat feces, especially away from yards and playgrounds, is important.
  • 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 non-covered sandboxes. Sandboxes that have fitted covers are popular and help to prevent infection of children with intestinal parasites.
  • Control of rodents is important since they may play a role in transmission of hookworms to cats.
  • Stool should be removed from litter boxes daily, if possible. Always wash hands after handling fecal material.

Can hookworms be transmitted to humans?

Feline hookworms do not infect humans internally. However, the tiny 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 good hygiene is practiced.

This client information sheet is based on material written by: Ernest Ward, DVM (modified by MAH Jan 2016)

© Copyright 2009 Lifelearn Inc. Used and/or modified with permission under license.

In the News