Worms in Cats — Symptoms & Treatment

Learn how to spot parasites early, treat them fast, and protect your cat from reinfestation.

Chat With a Vet Now
Health Condition

Intestinal worms are one of the most common parasitic infections in cats, affecting kittens and adults alike. Many infections go unnoticed until symptoms become visible—or until a vet finds worms during a routine exam. The good news is that worms are highly treatable, and prevention is straightforward once you know what to watch for.

Quick Facts

4 main types
Roundworms, tapeworms, hookworms, lungworms
Indoor cats at risk
Not just outdoor cats get worms
Treatable in days
Deworming medications work quickly
Fecal test confirms
Vet exam identifies the parasite type

Understanding Worms in Cats

Intestinal worms are parasites that live in a cat's digestive tract, feeding on nutrients meant for your cat. While some infections cause obvious symptoms, others remain silent until a vet discovers them during a fecal exam. Kittens, outdoor cats, and cats with weakened immune systems are especially vulnerable, but any cat—including indoor-only pets—can pick up worms.

  • Roundworms (Toxocara cati) are the most common type, especially in young kittens
  • Tapeworms (Dipylidium caninum, Taenia) often spread through fleas or eating infected prey
  • Hookworms (Ancylostoma) are less common but serious if untreated, especially in kittens
  • Lungworms (Aelurostrongylus abstrusus) infect the respiratory tract and are picked up from slugs, snails, or infected prey
  • Some worm infections can be passed to humans, making prevention important for your whole family

Signs and Symptoms to Watch For

Mild worm infections may cause no visible symptoms at all, but moderate to heavy infestations usually show clear warning signs. If you notice any combination of these symptoms, a vet visit is important to confirm the cause and start treatment.

  • Vomiting—sometimes with visible worms in the vomit
  • Diarrhea or soft stools, occasionally bloody
  • Weight loss despite normal appetite
  • Bloated or swollen belly, especially in kittens
  • Lethargy or reduced energy
  • Poor coat quality or dull appearance
  • Visible worms in stool or around the anus (especially tapeworms, which look like rice grains)

How Cats Get Worms

Transmission routes vary by worm type, but most infections happen through ingestion—either from contaminated food, water, soil, or contact with an infected animal. Indoor cats are not immune; worms can be brought in on shoes, handled through litter box cleanup, or transmitted from an infected kitten.

  • Eating infected prey (mice, birds, insects, slugs, or snails) — the most common route for outdoor and hunting cats
  • Ingesting larvae or eggs from contaminated soil, feces, or environmental surfaces (fecal-oral transmission)
  • Mother-to-kitten transmission through nursing (transmammary spread of Toxocara cati larvae)
  • Flea ingestion during grooming — fleas carry Dipylidium caninum tapeworm larvae
  • Contact with contaminated litter boxes, especially in multi-cat households with poor scooping routines
  • Walking through and then grooming paws after exposure to larval-infected environments

Diagnosis and Testing

Your vet will diagnose worms through a physical exam and a fecal flotation test, which looks for parasite eggs under a microscope. Sometimes a single test misses an infection, so your vet may recommend repeat testing if symptoms persist but the first result is negative.

  • Bring a fresh stool sample to the vet (collected within the last 24 hours)
  • Some worms (like tapeworms) may be visible to the naked eye
  • Your vet may ask about outdoor exposure, flea history, and when symptoms started
  • Bloodwork is occasionally needed if the cat is very ill or complications are suspected

Treatment Options

Deworming medications are safe, effective, and work quickly—most cats show improvement within days. The type of medication depends on which parasite your vet identifies, and some medications target multiple worm types. Your vet will prescribe the right dose based on your cat's weight and the infection severity.

  • Oral medications (tablets or liquid) are the most common treatment
  • Injectable dewormers are available for cats that won't take pills
  • Follow-up doses may be needed 2-4 weeks later to catch newly hatched parasites
  • Treat all cats in the household at the same time to prevent reinfection
  • If fleas are present, flea treatment is essential to prevent tapeworms

Prevention and Long-Term Care

Regular deworming and good hygiene are the best defenses against worm infections. Kittens typically need deworming every 2 weeks until 12 weeks old, then monthly until 6 months; adult cats benefit from annual testing and prevention. Keeping your home clean and your cat on flea prevention significantly reduces infection risk.

  • Scoop litter boxes daily and wash them weekly with hot water
  • Keep outdoor areas free of feces and use covered sandboxes if children play outside
  • Use monthly flea prevention year-round—many products also prevent some worms
  • Feed raw or undercooked meat with caution; freeze meat at -4°F for 7 days to kill parasites
  • Ask your vet about annual or bi-annual fecal testing for indoor cats
  • For outdoor or hunting cats, monthly deworming may be recommended

Frequently Asked Questions

Can I catch worms from my cat?

Some roundworms and hookworms can infect humans, particularly young children who play in soil or don't wash hands after touching a cat. The risk is low with good hygiene, but it's another reason to treat infections promptly and keep litter areas clean. Wash your hands after handling your cat, cleaning the litter box, or playing in soil.

How long do deworming medications take to work?

Most oral dewormers start killing parasites within hours, and you may see dead worms in the stool within 24 hours. Symptoms like diarrhea and vomiting often improve within 3-5 days, though weight loss can take longer to reverse. Follow-up doses are usually given 2-4 weeks later to catch parasites that weren't mature during the first treatment.

My indoor cat has never been outside—can it still get worms?

Yes, indoor cats can get worms through contaminated food, water, soil brought in on shoes, or from an infected kitten. Even a single mosquito or flea can carry parasites into your home, so indoor cats aren't risk-free. Regular fecal testing and preventive deworming are still important.

What's the difference between roundworms and tapeworms?

Roundworms look like spaghetti in the stool or vomit and are more common in kittens; tapeworms look like rice grains and are typically spread by fleas. Both are treated with different medications, which is why proper diagnosis is important. Your vet will recommend the right dewormer based on what they find.

Do I need to deworm my cat if there are no symptoms?

Yes—many mild infections cause no visible symptoms but can still affect your cat's growth and immune health, especially in young cats. Annual fecal testing and preventive deworming for kittens are standard vet recommendations. If your cat is outdoors or has exposure risk, more frequent testing may be advised.

How often should my kitten be dewormed?

Kittens are typically dewormed every 2 weeks starting at 6 weeks of age until they're 12 weeks old, then monthly until 6 months. After that, annual or bi-annual fecal exams and preventive deworming are recommended depending on lifestyle. Your vet will create a schedule based on your kitten's risk factors.

Can worms come back after treatment?

Yes, reinfection is possible if your cat is re-exposed to contaminated soil, prey, or fleas. Preventing reinfection requires good hygiene, flea control, and limiting outdoor hunting. If your cat gets worms repeatedly, your vet can discuss ongoing preventive deworming or environmental changes.

What should I do if I see worms in my cat's stool?

Collect a fresh sample and call your vet right away—you don't need to wait for a scheduled appointment. Bring the sample with you so your vet can identify the worm type and prescribe the correct treatment. Start deworming as soon as your vet recommends to prevent symptoms from worsening.

Related Cat Guides

Why do Cats Make Biscuits — Explained

Cat Tail Meanings — What Every Position Says

What Does Catnip do to Cats — Explained

Feline Herpes — Symptoms & Treatment

Why is my Cat Meowing so Much — Explained

Cat Sleeping Positions — Explained

Medical disclaimer: This content is for general informational purposes only and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a licensed veterinarian about your cat's health, especially for any urgent symptoms or before starting a new treatment. Meow Mobile members get 24/7 access to licensed vets via chat and video.

Get Expert Vet Guidance Anytime

Chat with a licensed veterinarian 24/7 to discuss worm symptoms, prevention, or treatment options for your cat—no appointment needed.

Get Started