Pet InfoRx®
Cat Intestinal Parasites

Your cat has an intestinal parasite! Now what?

This pet information prescription will help you know what to do, how to make your cat more comfortable, and how to prevent this from happening in the future.


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Common Types of Worms in Cats

cat parasites and wormsIntestinal parasites (whipworms, roundworms, hookworms, and tapeworms) are preventable, but the key is consistent, year-round use of effective preventatives on all of your pets (including indoor-only dogs and cats). There are many choices of preventatives and some are better (and safer) than others. Your veterinarian is truly your best resource for figuring out a safe and effective parasite prevention program for your cat.

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What Are Intestinal Parasites?

Intestinal parasites are worms that live in your cat’s stomach or intestines (their gastrointestinal or GI tract). There are multiple species of parasites that can infect cats, including roundworms, hookworms, tapeworms, and whipworms. While some cats may not show symptoms if they have low numbers of worms, other cats, even with only a few worms, will have vomiting, diarrhea, weight loss, and a lack of energy. Sometimes, you will know your pet is infected with intestinal parasites when you see worms or parts of worms in your cat’s poop.

If intestinal parasites are left untreated, your cat could suffer from significant pain, become malnourished, underweight, and even spread the parasites to other people and pets.

Potential for Zoonotic Diseases

Some intestinal parasites can be transmitted to humans (also known as zoonotic transmissions). So, it’s essential to treat your cat’s parasites to prevent spread to people and other pets.

Be sure to wash your hands any time you’re cleaning the litter box or come in contact with fecal material and clean up all inside accidents immediately. And it's also very important that all your pets be on parasite preventive medication to prevent the transfer of disease.

How Did This Happen?

Cats can become infected with intestinal parasites when they:

  • ingest contaminated stool from another animal, 
  • eat a worm-infested animal (usually a rat or mouse),
  • eat or step in contaminated soil (eggs and worms can live in the earth),
  • or in the case of tapeworms, a cat is bitten by an infected flea that will transmit the parasite.

Kittens can become infected by ingesting milk from their mother if she has intestinal parasites.

What You Should Do If Your Cat Has Parasites

Follow your veterinarian’s instructions to administer any anti-parasiticide products, also called dewormers. Depending on the parasite your cat has, their symptoms, and your geographic area, your veterinarian may treat cat in their office with a liquid or injectable dewormer or send home an oral tablet or topical liquid that you will administer in between your cat’s shoulder blades.

Your veterinarian will likely also recommend rechecking a fecal sample and/or providing a second dose of dewormer, so be sure to follow their directions on this to ensure that the parasites have been fully destroyed!

Keep Your Cat Comfortable

The best thing you can do is to use the medication your veterinarian prescribed. Keep a close eye on what your cat is eating and monitor their litter box habits. If your cat has gastrointestinal (GI) symptoms, like diarrhea or vomiting, they may also need a special GI-friendly diet that is easily digested as their stomach and intestines recover. Your vet may recommend a specific food or suggest a bland diet like cooked rice and baked chicken. A probiotic like Purina's FortiFlora® may also be recommended to help your cat’s GI system return to normal sooner.

comfortable cat

How Do You Know Things Are Improving?

If your cat was experiencing any symptoms (vomiting, diarrhea, lack of energy), these should improve within a few days of treatment. You should not see any worms or pieces of worms in your cat’s stool or litter box within one week, and their stool should be becoming more solid. Cats that had been underweight should begin gaining weight.

How Do You Know When Things Are Not Improving? What You Should Do.

If your cat is still vomiting, having diarrhea, not eating, or acting as if they don’t feel well within 4–5 days after their treatment, you should reach out to your veterinarian to determine the next steps.

If you are still seeing worms or pieces of worms in their stool after one week, your veterinarian may wish to prescribe a second dose or a different dewormer. They may also recommend that you bring in another fecal sample from your cat's litter box to ensure that another type of parasite isn’t present. Be sure to ask them for their guidelines on how old the sample can be before bringing it in – a general rule of thumb is to bring in a sample that is no older than 12 hours old.

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How to Prevent This from Happening in the Future

Luckily, intestinal parasites are often very preventable. It’s important to start by treating your cat, and all animals in your home, for any intestinal parasites as soon as they are diagnosed. Next, your cat should be on a regular parasite prevention regime, ESPECIALLY if they go outside. Luckily, many external parasite preventative products (for fleas, ticks, and heartworm disease) also address internal parasites, so it’s easy to make this a one-and-done.

After your cat’s infestation has seemingly resolved, it’s important to recheck a fecal sample to ensure that treatment was fully successful. Depending on the parasite and your geographic area, 1–2 rechecks spaced a few weeks apart is recommended.

Remember to get a fecal sample checked on all pets in your household at least yearly in order to detect any parasites before they become a problem in the future.

The Pet InfoRx® is made possible, in part, through our partnership with AlignCare®.

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