Introduction: When It’s Time to Deworm Your Cat
Most cat parents never expect to see tiny white segments in the litter box—or worse, squirming worms in their cat’s stool. But internal parasites are more common than we like to imagine, and deworming isn’t just for outdoor cats. Even indoor cats can pick up worms through fleas, grooming, or shared spaces with other pets.
At SnuggleSouls, we believe that a well-informed deworming plan is one of the most underrated ways to protect your cat’s health—especially if you’ve noticed signs like vomiting, diarrhea, bloating, or scooting. With the right treatment, most cats bounce back quickly and feel noticeably better within days.
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Want the full breakdown of how cats get worms, including causes, symptoms, and prevention strategies? Start with our all-in-one resource:
👉How Do Cats Get Worms? Causes, Symptoms, and Treatment
In this post, we’re zooming in on what to do after a diagnosis:
We’ll walk you through the most effective deworming strategies—both prescription and natural—explain how to pick the right treatment for your cat’s worm type, and share crucial follow-up steps to stop reinfestation before it starts.
Let’s make worms one less thing you ever have to worry about.
Treatment: Deworming Strategies for Cats
If your cat is diagnosed with worms (or even if worms are just suspected based on symptoms), the solution is usually a course of deworming medication. Modern dewormers are safe, effective, and available in a variety of forms (tablets, spot-on topical treatments, pastes, or injections), making it relatively easy to treat your feline friend.
However, the specific medication and protocol can vary depending on the type of worm. Here’s how we approach deworming, along with some natural considerations:
Veterinary Dewormers (Anthelmintics)
These are medications specifically designed to kill and expel worms. Different drugs target different worms, so it’s important to use the right one(s) for your cat’s infection:
Roundworms and Hookworms
These are often treated with broad-spectrum dewormers like pyrantel pamoate or fenbendazole. Pyrantel (a liquid or tablet) is very effective against roundworms and hookworms – it basically paralyzes the worms’ muscles so they let go of the intestine and get passed out.
Kittens with roundworms typically get pyrantel doses every 2-3 weeks until they’re a few months old. Fenbendazole (a powder or liquid given over several days) can also treat round, hook, and certain lungworms or whipworms.
It’s common for vets to use a combination product that covers these common GI worms in one go. Many over-the-counter “all wormer” products for cats contain pyrantel among other ingredients.
Tapeworms
The go-to treatment is praziquantel, a drug that targets tapeworms specifically. Praziquantel causes tapeworms to lose their resistance to digestion – essentially, the worm gets digested by the cat or is passed in pieces.
It’s very effective and usually given as a single dose (either orally or via an injection at the vet).
Often, vets use a combination product (for example, a topical dewormer that has praziquantel + something for round/hookworms) so that all common worms are treated.
Important: if your cat has tapeworms, you must address fleas too, otherwise reinfection will occur quickly.
Whipworms
Though rare in cats, whipworms can be treated by fenbendazole or a higher-dose longer course of pyrantel, among other options. Some monthly heartworm preventatives (like certain milbemycin or moxidectin based products) also control whipworms. Your vet will choose a protocol if whipworm eggs are found.
Heartworms
There is no safe heartworm adulticide for cats (the medication used in dogs, melarsomine, is too dangerous for felines). Therefore, treatment of heartworm-positive cats is mostly supportive care and symptom management.
Vets may prescribe corticosteroids to reduce lung inflammation, bronchodilators to help breathing, or even place the cat on oxygen if needed In some cases, surgical removal of heartworms via the jugular vein has been attempted if there are many worms, but often there are only 1-3 worms in cats which can make surgery tricky.
The cat’s immune system might eventually kill the worms, but as they die they can cause acute shock or respiratory failure. So essentially, preventive monthly heartworm medication is the best “treatment” – we want to avoid cats ever getting heartworms.
If a cat does get heartworm disease, a veterinarian will develop a careful management plan (which might include long-term steroids, monitoring, and treating any secondary infections like lung damage or heart failure).
Lungworms
Treatment often involves fenbendazole given over a longer period (e.g. 10-14 days), or other anthelmintics like ivermectin in certain cases. Some topical dewormers (emodepside, part of the Profender® spot-on) are effective against lungworms too.
The vet may also prescribe anti-inflammatory medications if the lung inflammation is significant. Follow-up fecal tests are done after treatment to ensure the lungworm larvae are gone.
Other Rare Worms
Stomach worms (Physaloptera) can be treated with pyrantel or ivermectin; bladder worms often clear with fenbendazole or ivermectin; liver flukes require a higher dose of praziquantel or a medication like triclabendazole (depending on the fluke species).
These are infrequent enough that most cat owners will never encounter them, but your vet will know how to handle them if needed.
Strictly Follow the Deworming Schedule
ome worm medications are one-and-done, but many require multiple doses or a series of treatments.
For instance, pyrantel kills adult roundworms but not migrating larvae, so kittens need repeat doses every 2-3 weeks to catch newly matured worms until the cycle is broken.
Fenbendazole is often given for 3 days in a row (for Giardia or lungworm, it might be longer). If the vet dispenses a course, be sure to give every dose on time.
We can’t stress this enough: always complete the full deworming regimen as directed, even if your cat seems better after one dose. Also, schedule that follow-up fecal exam if your vet recommends it – it’s the only way to confirm all worms are gone and no further treatment is needed.
Skipping rechecks might allow a small remaining population of worms to bounce back.
Potential Side Effects
Most modern dewormers are well tolerated by cats. You might see some mild digestive upset (like soft stool or a bit of vomit) after a dose – sometimes as a result of worms dying off. It’s also not uncommon to literally see worms being expelled in the feces after treatment (don’t be alarmed, that’s good!).
If your cat vomits immediately after taking an oral dewormer, let your vet know – the dose may need to be repeated.
Severe side effects are rare; in very high worm burdens, the die-off of too many worms at once can theoretically cause a blockage or allergic-type reaction, which is why vets may adjust the treatment approach if they suspect an enormous load (e.g. dose first to kill some, then follow up with another dose).
Always use cat-specific products in the correct dosage. Never give a cat a dewormer made for dogs – some dog dewormers have combinations (or strengths) that are unsafe for cats.
Deworming All Pets & Environment
If one of your cats has worms, your vet may advise deworming your other pets as well, since many parasites spread via shared environment.
This often includes dogs in the household, which might be reservoirs for roundworms or hookworms that cats can catch (or vice versa). Many broad-spectrum dewormers used by vets are safe across species in appropriate doses.
Additionally, cleaning the environment is part of treatment: thoroughly scoop and discard all litter, and sanitize litter boxes with boiling water or a pet-safe bleach solution to destroy any lingering eggs.
Wash any bedding or rugs where your cat lounges, in case eggs or tapeworm segments are there.
For fleas, use appropriate flea treatments on all animals and consider treating the home (vacuuming carpets, washing fabrics, maybe using flea sprays or diatomaceous earth in crevices) to prevent re-infestation that would lead to tapeworm recurrence.
Follow-Up and Ongoing Prevention
After treatment, you should see your cat feeling better – weight stabilizing, stool quality improving, coat looking shinier, etc. But don’t stop there.
Follow-up fecal tests (usually about 2-4 weeks after finishing deworming) are important to ensure the worms are truly gone. Sometimes a second round of treatment is needed. Once your cat is clear, stick to a preventive regimen (which we’ll detail in the next section) to avoid new infections.
Many vets will recommend putting your cat on a monthly parasite preventive that not only handles fleas and ticks but also keeps worms at bay (for example, there are topical solutions that prevent heartworms, kill fleas, and also contain a dewormer for round/hookworms).
These broad preventives can quietly keep your cat worm-free in the background. If you prefer not to use year-round medications, then plan to screen and possibly deworm your cat multiple times a year, especially if they go outdoors.
Conclusion
It’s easy to think of deworming as a simple pill or drop and move on—but as we’ve explored, treating worms in cats is far more nuanced than that. It’s not just about getting rid of parasites—it’s about restoring your cat’s comfort, vitality, and long-term health.
Whether it’s a kitten with roundworms, a senior cat coughing from lungworm, or a tapeworm brought in by a single flea—the right treatment, given at the right time, makes all the difference.
But skipping doses, ignoring subtle signs, or relying solely on natural remedies can turn a treatable issue into a recurring one. Worms steal nutrients, energy, and joy from our cats—often quietly.
So don’t wait. If your cat shows symptoms—or even if you’re just unsure—talk to your vet. Follow through on the full plan. And once your cat is back to her bright-eyed self, take that win seriously. Because a worm-free cat is a thriving cat.
You’re not just treating worms. You’re removing a hidden burden—and helping your cat live the light, playful, parasite-free life she deserves.
We’d love to hear your story. Share your experiences, join our cozy community of cat lovers at SnuggleSouls. Together, let’s celebrate every precious, whiskered moment.
FAQ
How long does it take for deworming to work in cats?
Most cats begin to expel worms within 24–48 hours of taking the medication. However, full effectiveness depends on the worm type and whether follow-up doses are given.
Can I use a natural remedy instead of prescription medication?
Natural dewormers like pumpkin seeds or food-grade diatomaceous earth may offer some benefit, but they are generally best used as supplements—not replacements—for vet-approved treatments.
What if my cat vomits after taking a dewormer?
If your cat vomits shortly after taking an oral dewormer, contact your vet—it may require another dose or a different form (like an injection).
Do I need to treat my other pets too?
Yes. If one cat has worms, it’s likely others are at risk. Many intestinal worms are contagious through shared environments. Treat all household pets accordingly, under vet guidance.
How can I prevent future worm infestations?
Regular use of monthly parasite preventives, flea control, keeping litter boxes clean, and fecal testing 1–4 times a year are your best defenses.
References
Bowman, D. D. (2020). Georgis’ Parasitology for Veterinarians (11th ed.). Elsevier.
Capári, B., Hamel, D., Visser, M., Winter, R., Pfister, K., & Rehbein, S. (2013). Parasitic infections of domestic cats, dogs and red foxes in Hungary. Veterinary Parasitology, 192(1-3), 161–167. https://www.sciencedirect.com/science/article/abs/pii/S0304401712005572?via%3Dihub
Companion Animal Parasite Council (CAPC). (2023). Parasite Prevalence Maps & Guidelines for Feline Deworming.
Venco, L., Marchesotti, F., & Manzocchi, S. (2015). Feline heartworm disease: A ‘Rubik’s cube’ for the veterinary practitioner. Veterinary Parasitology, 208(1-2), 2–11. https://www.sciencedirect.com/science/article/abs/pii/S0304401715000333?via%3Dihub
American Association of Feline Practitioners (AAFP). (2020). Feline Zoonoses Guidelines. Retrieved from https://catvets.com
Traversa, D., & Di Cesare, A. (2016). Veterinary Parasitology in Cats: Current Trends and Emerging Issues. Parasitology Research, 115(7), 2339–2349. https://link.springer.com/article/10.1007/s00436-016-5022-5
Merck Veterinary Manual. (2022). Anthelmintics for Cats. Retrieved from https://www.merckvetmanual.com