Veterinarian-written / veterinarian-approved articles for your cat.

Cat Digestive Tract Worms


The digestive tract of cats is host to a number of parasites. Some of these are a risk for people, especially those who are immune compromised. It is important for you to know about these parasites.

Parasitic worms are very common in cats. Bring a sample of stool (also called feces or bowel movement) so that your veterinary hospital can identify worms lurking in your pet. Note that successful treatment generally requires multiple doses of a wormer, and follow up stool checks will be done to confirm that the infestation has been cleared.


Cat Roundworms

These are very common parasites of cats. They are most prevalent in kittens as they can easily be transmitted from queen to her offspring.

The roundworms, Toxocara and Toxascaris have immature forms called larvae, and the larvae of Toxocara are capable of migrating in human tissue, which can lead to organ or eye problems. Children may contact the larvae in the soils and grass of parks while playing in locations where citizens have walked worm infested dogs and have not cleaned up their poop, or where neighborhood cats have used sand boxes as litter boxes! Unfortunately, once the rain falls and the sand gets stirred up, a watchful parent will not be aware of the potential dangers lurking in the play areas. Having children wash their hands after playing and before putting their hands in their mouth (or eating) is an important hygiene measure.

Kittens infested with roundworms usually look normal, or they may be stunted with a poor haircoat. In young cats, heavy infestation with roundworms can lead to a tender abdomen, poor appetite, weakness, and diarrhea. Worms infrequently can be seen in stool or rarely, in vomit. A very heavy worm burden may even cause intestinal blockage.

Cat Hookworms

These parasites (Ancylostoma, Uncinaria) live in the small intestine. Hookworms are blood-sucking parasites; infestation can lead to skin irritation, anemia, diarrhea, and inflammation of the small intestine. Hookworm infestation is especially harmful in young or debilitated kittens. Transmission occurs either via nursing or skin penetration by larvae. Skin of people can also be penetrated, leading to skin lesions!

Common clinical signs in cats include diarrhea, which may be dark or tarry looking, decreased appetite, and general unthriftiness. Veterinary diagnosis is based on history, physical examination, and a fecal flotation test.

Cat Tapeworms

Cestodes, or tapeworms, are common in the United States . The two most common types of tapeworm of cats are Taenia and Dipylidium. Each species has a different route of transmission—through hunting, and fleas respectively.

Signs of tapeworm infestation include worm segments in stool or at the back end in the fur, and “scooting” along the ground. Sometimes segments may be found crawling across the floor, or dried up on surfaces, with a rice-grain appearance. Definitive diagnosis is made by observing adult segments or microscopic identification of eggs in the feces. One must prevent fleas and/or mouse-hunting in order to prevent these tapeworm infestations.

Cat Strongyloides Worms

Strongyloides worms are found in the intestines. Transmission is usually via colostrum from the mother to offspring. Infective larvae are also capable of penetrating the skin, making it transmissible to humans. Signs include diarrhea, and skin inflammation. Diagnosis is made by your veterinarian when Strongyloides eggs are observed in a fecal exam.

Other Cat Parasitic Worms

Stomach worms, lungworms, heartworms, worm larvae under the skin (Cuterebra), and fluke worms also can infest cats. Other parasite eggs may be swallowed during hunting and can be found in the feces, but are not necessarily undergoing a presence and life cycle in the cat. The important thing to know is that diagnosis of parasitic worms of cats at home is only rarely possible, and if you see tape segments or roundworms, usually this indicates a HEAVY worm burden. Take a fresh stool sample in at the interval recommended by your local veterinarian to help keep these nasty worms under control!

Disclaimer: This website is not intended to replace professional consultation, diagnosis, or treatment by a licensed veterinarian. If you require any veterinary related advice, contact your veterinarian promptly. Information at is exclusively of a general reference nature. Do not disregard veterinary advice or delay treatment as a result of accessing information at this site.