Common Worms That Infect House Cats

Regular vet checkups are the key to preventing severe worm problems.
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Outdoor cats are at high risk of contracting worms, but even house cats can pick up unwanted guests. A group of internal parasites, collectively called worms, are among the most insidious pests that plague domesticated felines. Most worms are intestinal parasites, but some can infest other vital organs as well.


Roundworms are intestinal parasites that can infect cats, dogs and many other animal species. They are the most prevalent intestinal parasites in felines and are very common in kittens, according to Cornell University College of Veterinary Medicine. Adult cats ingest roundworm eggs by swallowing fleas or eating infected rodents. Kittens can acquire worms while nursing from their mother. Roundworms are only life-threatening for adult cats when they are present in large numbers, but even a few can be deadly for kittens. The worms can grow up to 5 inches long, which is enough to clog your pet's digestive tract and cause serious discomfort. Routine deworming procedures are effective for removing these common parasites.


Hookworms are also intestinal parasites, but they are much smaller than roundworms. They also have the disturbing ability to infect humans as well, so it is important to have your pet examined regularly and treated promptly. Hookworms are transmitted like roundworms, but they can also invade your pet's body by penetrating through the skin and traveling to his lungs, according to Rural Area Veterinary Services. These worms suck blood from the lining of your pet's intestines. It is important to have all young kitties checked for these worms in the first few months after birth.


Where there are fleas, there may also be tapeworms. Even if your cat is strictly an indoor pet, it is not impossible for fleas to find their way through your front door. Tapeworms require fleas to complete their life cycle, so flea treatments are an effective measure for preventing tapeworms in your pets. These worms are intestinal parasites and are often visible in your cat's stool if he is infested. However, the absence of white rice-like worm segments in stool does not necessarily mean your pet doesn't have tapeworms.

Other Common Worms

Most of the common worm-like parasites reside in the digestive tract, but there are a few worms that can make their home outside your kitty's intestines. Heartworms are deadly and it can take months to treat an infected animal. You should take your pet in for checkups at least twice a year because heartworms may not cause visible symptoms until it is too late. Some worms can also infest your cat's lungs, although these parasites are a bigger problem for outdoor pets. Snails, slugs and birds can transmit lungworms to cats and dogs, according to the ASPCA.

Always check with your veterinarian before changing your pet’s diet, medication, or physical activity routines. This information is not a substitute for a vet’s opinion.

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