How to Tell If Your Cat or Kitten Has Worms
By Dr. Zubair Khalid, DVM, MS, PhD ·
If you are asking how to tell if my cat has worms, start by watching the litter box, the belly, and the coat. Many infected cats show no obvious signs at all, while others have vomiting, diarrhea, a dull coat, or a swollen abdomen. Kittens tend to show signs sooner and more dramatically than adult cats.
This article is educational and is not a substitute for veterinary diagnosis or treatment.
Quick Answer
- Check the stool and the area around the tail for white, rice-like segments or spaghetti-like worms, which can mean tapeworms or roundworms [1].
- Watch for a potbelly, poor growth, dull coat, vomiting, or diarrhea, especially in kittens under 3 months old [2].
- Know that many cats with worms look completely normal, so a yearly fecal test is the only reliable way to know [3].
- Never guess at a dewormer or dose. Your veterinarian calculates the right product and amount from your cat's weight and health.
- Treat fleas too, because tapeworms spread through fleas, and keep kittens on a deworming schedule set by your vet [2].
What Worms in Cats Actually Are
Worms are internal parasites that live in your cat's digestive tract or other organs. The most common ones in cats are roundworms, hookworms, and tapeworms [3]. Roundworms are the most common intestinal parasite of cats, affecting 25% to 75% of cats, with higher rates in kittens [1].
Roundworms are cream-colored and about three to five inches long. They live in the intestine and do not attach to the intestinal wall. They survive by eating food your cat has swallowed [1]. Tapeworms and hookworms behave differently, but all of them can cause problems if they build up in numbers.
Cats can also get external parasites like fleas and ticks, tiny single-celled organisms called protozoa, and heartworms [3]. This article focuses on the worms you can sometimes see or test for.
Signs of a Cat With Worms
What you may see in the litter box
Adult roundworms may be vomited or passed in feces [2]. They look like thin, pale noodles. Tapeworm segments look like small grains of rice or sesame seeds and may move near the tail or in fresh stool. If you see either, save a sample and call your vet.
What you may see in your cat
Signs of a cat with worms can be subtle. Often there are no signs at all, though weight loss and anemia can occur [2]. When signs do appear, common ones include diarrhea, poor growth, a dull coat, or a distended, swollen abdomen [2]. Kittens with a heavy roundworm load often have that classic potbelly look.
A large study of cats that died in southern Brazil found that most parasitized animals had pale mucous membranes, which suggests anemia. About 71.6% of the parasitized cats had pale gums, and 41.8% were in only regular body condition while 28.3% were thin [4]. Pale gums are a reason to see a vet promptly.
What do kittens with worms look like
Kittens are the group most likely to look unwell. They may have a round belly, a rough coat, and slower growth than their littermates [2]. Roundworm larvae can pass to kittens through the mother's milk, and adult parasites can be found in the small intestine of kittens as early as 3 to 4 weeks of age [2]. That is why deworming starts young.
If your kitten also has loose stool, see Cat Diarrhea with Worms: Causes and Treatment Options.
| What you notice | What it may mean | What to do |
|---|---|---|
| Rice-like segments near the tail | Tapeworm | Call your vet, treat fleas |
| Long, thin worms in vomit or stool | Roundworm | Save the sample, book a visit |
| Potbelly and poor growth in a kitten | Roundworm or other worms | See a vet soon |
| No signs at all | Possible silent infection | Yearly fecal test [3] |
| Pale gums, weakness | Anemia, possibly hookworms | Contact a vet the same day |
Causes and Risk Factors
Cats become infected with Toxocara cati, a common roundworm, by ingesting eggs from contaminated soil or by eating rodents that carry the larvae [1][2]. Kittens can also get larvae through their mother's milk, sometimes soon after birth [1]. Another roundworm, Toxascaris leonina, spreads through infective eggs in the environment or larvae in rodents. It cannot pass through the placenta or milk, so cats under two months old rarely have it [1].
Outdoor access raises risk. So does hunting. Adult cats generally have some resistance to roundworm infection, but immunity can be suppressed around the time a queen gives birth, and she may shed large numbers of eggs in her feces [2].
Fleas matter for tapeworms. If your cat has fleas, it can get tapeworms by grooming. This is one reason flea control and worm control go together.
How Vets Diagnose Worms
Your veterinarian will ask about your cat's history, lifestyle, and any signs you have seen. Then they will test a stool sample. Regular stool checks are recommended once a year or more, especially for kittens or outdoor cats [3].
Fecal testing is not one single test. A comparison of lab methods found that different techniques catch different parasite stages. The Faust technique was better for low-density structures, while the Ritchie technique worked well for high-density structures. Neither method alone reached a sensitivity of at least 70%, which is why labs often combine techniques [5].
In a large United States study of 15,395 fecal exams from client-owned cats in 2023, 13.52% were positive for at least one parasite and 2.10% had multiple parasites. The most common finds were Giardia species at 4.82%, Toxocara cati at 4.75%, and Cystoisospora species at 3.40% [6]. Shelter cats can carry even more. In East Tennessee shelters, 43.5% of cats tested positive for at least one parasite, with Toxocara cati and Cystoisospora felis the most common [7].
That gap between healthy-looking pets and positive tests is why vets test instead of guessing.
Treatment Options
Treatment depends on which worm your cat has. Your veterinarian will choose a dewormer based on the parasite, your cat's age, weight, pregnancy status, and other health conditions. The dose is calculated from your pet's weight and health, so never use a product meant for another animal or a human dewormer.
Kittens should be dewormed on multiple occasions in the first 3 months of life [2]. Some monthly heartworm preventives also prevent roundworm infection [2]. If your cat has tapeworms, flea treatment is part of the cure, because fleas carry the tapeworm stage that infects cats.
Do not rely on a single dose. Some worms need repeat treatment, and some products only cover certain species. Bring the stool sample to your visit if you can, and ask your vet whether a follow-up fecal test is needed.
How to Tell If Your Cat Still Has Worms
This is one of the most common questions after treatment. The honest answer is that you often cannot tell by looking. A cat can carry worms and show no signs [2]. Visible worms may disappear after treatment, but eggs and larvae can remain.
The reliable check is a repeat fecal exam. Your vet will tell you when to bring in a fresh sample, usually after the treatment course is finished. Keep watching for the same signs you saw before, such as diarrhea, vomiting, a dull coat, or a potbelly in a kitten [2]. If signs return or never improve, call your vet.
If your cat has skin or coat problems that you are not sure about, see Ringworm In Cats. Ringworm is a fungus, not a worm, and it needs different treatment.
Recovery, Outlook, and Long-Term Management
Most cats recover well once they are on the right dewormer and any anemia or diarrhea is managed. Kittens with heavy infections may need extra time and nutrition to catch up on growth.
Long-term management is mostly about routine testing and prevention. Have stool checked at least once a year, and more often for kittens or outdoor cats [3]. Keep flea control current. If your cat hunts, assume ongoing exposure and talk with your vet about a prevention plan.
Some worms can infect people. The parasite that causes toxoplasmosis can pass into cat droppings, and people can be exposed when they clean an infected cat's litter box. Pregnant women, young children, and anyone with a weakened immune system are at higher risk [3]. Wash your hands after scooping, and ask your vet about your household's specific risks.
Prevention
Prevention is simpler than treatment. Here is what works.
- Test stool at least yearly, and more often for kittens and outdoor cats [3].
- Deworm kittens on the schedule your vet sets, starting in the first months of life [2].
- Control fleas, since tapeworms spread through them.
- Keep cats indoors when possible to reduce hunting and soil exposure [1].
- Wash hands after handling litter, soil, or raw meat.
- Ask your vet whether a monthly preventive that also covers roundworms fits your cat [2].
If your cat has urinary signs along with worms, those are separate problems. See What Are The Signs That My Cat Has A Urinary Tract Infection.
Limitations and When to Contact a Veterinarian
No article can tell you what is happening inside your cat. Individual cases need a veterinarian who can examine your pet and test a sample.
Contact a vet the same day if your cat has pale gums, repeated vomiting, ongoing diarrhea, or seems weak or depressed. These can point to anemia or dehydration [2][4].
Go to an emergency clinic now if your cat is collapsing, struggling to breathe, having seizures, or cannot stand. These are emergencies, not wait-and-see problems.
Book a routine visit if you see worms in stool or vomit, if your kitten has a potbelly or is not growing well, or if you simply want a fecal test [3][2]. For possible poisoning, call the ASPCA Animal Poison Control Center at (888) 426-4435 or the Pet Poison Helpline at (855) 764-7661.
Frequently Asked Questions
Can I get worms from my cat?
Yes, some cat parasites can infect people. Toxoplasmosis can pass into cat droppings and expose people who clean the litter box, and pregnant women, young children, and people with weakened immune systems are at higher risk [3]. Wash your hands after scooping and talk with your vet about your household.
Do all cats with worms show signs?
No. Often there are no signs at all, though weight loss and anemia can occur [2]. That is why yearly fecal testing matters even when your cat looks healthy [3].
Can I see worms in my cat's poop?
Sometimes. Roundworms may be vomited or passed in feces, and they look like thin, pale noodles [2]. Tapeworm segments look like rice grains. If you see either, save the sample and call your vet.
Are worms in kittens different from worms in adult cats?
Kittens are more likely to get roundworms from their mother's milk and to show signs like a potbelly and poor growth [1][2]. Adult cats often have some resistance, so infections may stay quiet [2].
How soon after treatment should my cat feel better?
It varies with the worm type, the treatment, and how sick your cat was. Some signs improve within days, while anemia and poor growth take longer. Your vet will schedule a follow-up fecal test to confirm the worms are gone.
Related Articles
- What Are The Signs That My Cat Has A Urinary Tract Infection
- Ringworm In Cats
- Signs Of A Urinary Tract Infection In My Cat
- Cat Diarrhea with Worms: Causes and Treatment Options
- How To Treat My Cats Ringworm At Home
- Symptoms My Dog Has Worms
References
- Gastrointestinal Parasites of Cats. Cornell University College of Veterinary Medicine.
- Gastrointestinal Parasites of Cats - Cat Owners. Merck Veterinary Manual.
- Parasites in Cats - Cat Owners. Merck Veterinary Manual.
- Gastrointestinal helminthiases associated with cause of death in dogs and cats from southern Brazil. Veterinary parasitology, regional studies and reports, 2026.
- Comparison of coproparasitological diagnoses in cats: evaluation of techniques and their combinations. The Journal of small animal practice, 2026.
- Prevalence and epidemiologic patterns of feline parasitism detected by fecal examination in the United States, 2023. Veterinary parasitology, 2026.
- Fecal prevalence and diversity of endoparasites in shelter dogs and cats from East Tennessee. Veterinary parasitology, regional studies and reports, 2025.