Fortunately, this type of parasite is less common in cats than other types of worms. Hookworms are the most harmful of the internal parasites because of the possibility of intestinal bleeding. The larvae first make their way to the lungs before settling in the intestines, where they grow into adult worms. Cats contract hookworms either by ingesting them directly, from larvae that penetrate their skin, or while still in utero from their mother.

Hookworm: These small internal parasites get their name from the hook-like teeth they use to attach themselves to the lining of the intestine, where they feed off your cat’s blood. You may be able to spot them in your cat’s feces or on the fur near the anus, but in some cases they are passed sporadically, meaning they may not always be found during a fecal examination Pieces of the worm then break off and are expelled through the feces. The worm will only come to maturity inside the intestine. Your cat may contract tapeworms by ingesting a flea infested with tapeworm eggs, either while grooming themselves or by eating an infested bird or rodent. Tapeworm: Tapeworms, another internal parasite, are flat and ribbon-like inside the intestine, but segments of the worms can resemble small grains of rice or sesame seeds in your cat's stool. On occasion, you may be able to see the roundworms moving around in your cat’s poop or vomit. The worms then produce eggs, which are eliminated through the feces. They steal nutrients from the food your cat ingests.

Roundworms measure anywhere between three to five inches long and look like spaghetti noodles. Roundworm: These are the most common intestinal parasites found in cats they’re also visible to the naked eye. Here’s a list of the most common worms found in felines:

Long flat pink worm in poop