What Causes Cats to Get Worms?

About 45 percent of all cats in the United States will at some time in their life suffer from a variety of of gastrointestinal parasitism, commonly referred to as worms, according to Cornell University. Stomach worms, roundworms, hookworms and tapeworms are the most common, and once inside a cats stomach, they can cause vomiting, diarrhea, anemia and dehydration as they divert essential nutrients and food away from where they are needed. They can be picked up in a number of ways.

  1. Rodents

    • Any cat owner can confirm that from time to time cats will catch and eat rodents or birds. While just following their basic instincts, this is a very common way for cats to catch worms, particularly roundworms. Cornell University states that roundworms are the most common intestinal parasite of cats with a prevalence of 25 percent to 75 percent. Rodents act as a transport host, and it only takes eating one worm for a cat to get infected.

    Fleas

    • Cats are very clean animals and lick and groom themselves throughout the day. While this does make them hygienic compared to other animals, this grooming can actually result in cats getting worms. Cats often swallow infected fleas, which pass the worm into the cat. Tapeworms are often transferred this way and are fairly harmless once inside the cat in terms of spreading diseases.

    Insects

    • Although cats do not generally feed on insects, they can occasionally pick up worms from them. Stomach worms are a nasty type of worm that is carried by insects, such as crickets and cockroaches. If a rodent, such as a mouse, eats these insects and then a cat comes into contact with it and eats it, then the chances of catching a worm increase. Cats infected with stomach worms may experience vomiting and loss of appetite.

    Larvae

    • A common type of worm found in the United States is the hookworm, which are less than a half inch long and are slender, thread-like worms that as adults live in the cat's intestine/ They affect between 10 percent and 60 percent of cats. Adult cats usually become infected by larvae that penetrate their skin. Once inside the cat, they move toward the lungs and intestines before developing into fully grown worms.