Hookworms are small, thin worms about 1⁄4 to 1⁄2 inches
(.6 to 1.3 cm) long. They fasten to the wall of the small intestines and draw
blood from the host. There are four species of hookworms that afflict the cat. Hookworms are not as
common in cats as they are in dogs. They are most prevalent in areas that have
high temperature and humidity (for example, in the southern United States),
where conditions are favorable for the rapid development and spread of
A cat acquires the disease by ingesting infected larvae in soil or feces or
by direct penetration of the skin (usually the pads of the feet). In rare
cases, a cat may acquire the parasite by eating mice that host the larvae. The
immature worms migrate through the lungs to the intestines, where they become
adults. In about two weeks, the cat begins to pass eggs in her feces. The eggs
incubate in the soil. Depending on conditions, larvae can become infective
within two to five days after being passed.
The veterinary community has divided vaccines into two main categories, with a smaller third
category. Core vaccines are vaccines that every cat should have at some time
in his life. Noncore vaccines are vaccines that only some cats need, depending
on factors such as geographic location and lifestyle. Other vaccines are also
available but are generally not recommended for any cats.
The typical signs of hookworm infestation are diarrhea, anemia, weight loss, and
progressive weakness. With a heavy
infestation, stools may be bloody, wine-dark or tarry-black, but this is
uncommon. A hookworm infestation can be fatal in very young kittens. The
diagnosis is made by finding the eggs in the feces.
Newborn kittens do not acquire the infection in utero but might via the milk
of the queen. Chronic infestation is a more common problem in adult cats than
it is in kittens.
Many cats who recover from the disease become carriers via cysts in the
tissue. During periods of stress or some other illness, a new outbreak can
occur as the larvae are released.
Treatment: Pyrantel pamoate and selamectin have become the deworming medications of choice
because of their safety and effectiveness. Milbemycin and ivermectin are also
very effective dewormers but are generally used only in older kittens and adult
cats. Two treatments are given two weeks apart. The stool should be checked to
determine the effectiveness of treatment.
Kittens with acute signs and symptoms require intensive veterinary
Public health considerations: A disease in humans called cutaneous larvae
migrans (creeping eruption) is caused by hookworm species. Larvae present in
the soil penetrate the skin and travel through the body. It causes lumps, streaks beneath the
skin, and itching. The condition is self-limiting.
WebMD Veterinary Reference from "Cat Owner's Home Veterinary Handbook"