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Morgan Taylor-Rakocevic, VMD

Program Manager Veterinary Standards

Dr. Taylor-Rakocevic has been with Banfield since 2017. She graduated with her VMD from University of Pennsylvania in 20...

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cat parasites: symptoms, risks, and how to protect your pet

Parasites are a common concern for cats of all ages and lifestyles — even those who live indoors full time! While the idea of parasites can feel unsettling, most are preventable and very manageable with routine veterinary care.

Cats can encounter parasites that live on the skin, live inside the digestive system, or are spread by insects or the environment. Some cause noticeable signs like itching, tummy troubles, or behavior changes, while others can sneakily go unnoticed without regular checkups.

Because every cat’s life looks a little different, parasite prevention isn’t one-size-fits-all. Regular wellness visits give your veterinarian a chance to spot risks early and recommend protection that fits your cat’s age, lifestyle, and environment.

If you’re unsure what your cat may be exposed to or want help building a prevention plan, your veterinary team can guide you through the options and help keep your cat protected year-round. Make an appointment

Illustration of a fluffy white cat scratching itself

What parasites can cats get?

Cats can be affected by several different types of parasites, which are often grouped by where they live and how they spread. Breaking parasites into categories can make them feel a bit less overwhelming and easier to understand. It also helps you know what symptoms to watch for and when it’s time to reach out to your veterinarian.

The major parasite categories in cats include:

External parasites

These live on the skin or in the fur and include fleas, ticks, and mites. They’re often associated with itching, hair loss, or visible debris in the coat or ears.

Intestinal parasites (worms)

These parasites live in the digestive tract and include roundworms, hookworms, and tapeworms. They can cause digestive upset, weight loss, or visible worms in stool or vomit — especially in kittens.

Vector-borne parasites

These are spread by insects. The most notable example is heartworm disease, which is transmitted by mosquitoes. A heartworm infection can be serious and unpredictable in cats.

Protozoal parasites

These are microscopic organisms such as Giardia, Coccidia, and Toxoplasma gondii. They’re often linked to diarrhea or dehydration and are more commonly diagnosed through veterinary testing rather than visible signs.

Some parasites cause obvious symptoms, while others can quietly fly under the radar without routine screening. Your veterinarian can help sort through which risks matter most for your cat based on age, lifestyle, and environment, then recommend prevention or testing when it makes sense — even before problems appear.

How do cats get parasites?

Cats can pick up parasites in more ways than many owners expect, and exposure doesn’t always involve close contact with other animals. Even cats who live strictly indoors can encounter parasites through everyday, easy-to-miss situations.

Two kittens play with a shoe on the floor

Common ways cats get parasites include:

Ingesting parasite eggs or larvae from contaminated soil, litter, food bowls, or grooming their own fur after exposure
Hunting or eating infected prey, such as rodents or insects, which can transmit intestinal parasites
Mosquito bites, which are how cats are exposed to heartworms
Swallowing fleas while grooming, a common route for tapeworm infections
Contact with contaminated surfaces, including shared litter boxes, bedding, or shoes tracked indoors
Nursing from an infected mother, which can pass roundworms to kittens early in life

That’s why the idea that “indoor cats don’t get parasites” isn’t accurate. Parasites can hitch a ride inside on shoes, insects, or other pets, and some (like heartworms) don’t require outdoor roaming at all. Your veterinarian can help assess your cat’s risk and recommend a preventive approach that feels appropriate and manageable.

Signs your cat might have parasites

Parasite symptoms can look different from cat to cat. Some show clear signs right away, while others may seem mostly normal at first, especially with mild or early infections. Noticing small changes in behavior, appetite, or appearance can make a big difference in catching issues early.

Here are common signs to watch for, grouped by parasite type:

Intestinal parasites

Visible worms or rice-like segments in stool, vomit, or around the rear
Diarrhea or soft stools
Weight loss despite a normal appetite
A dull or poor-quality coat
A rounded, pot-bellied appearance in kittens

Fleas

Frequent scratching, licking, or biting at the skin
Hair thinning or patchy hair loss, especially along the back or tail base
Tiny black specks in the fur (often called flea dirt)
Scabs or irritated skin from ongoing itching

Mites

Persistent head shaking
Red, inflamed ears or skin
Dark, crumbly debris in the ears
Hair loss or thickened skin in affected areas

Protozoal infections

Ongoing or recurrent diarrhea
Dehydration
Low energy or reduced interest in food

Heartworms

Coughing or labored breathing
Lethargy or sudden weakness
Vomiting or collapse in severe cases (rare, but serious)

If you notice any of these signs — especially if they linger or start to worsen — it’s a good idea to check in with your veterinarian. Many parasite-related symptoms overlap with other health concerns, and proper testing is the safest way to understand what’s going on and get your cat the right care.

Can cat parasites affect humans?

Some cat parasites can affect people, but the overall risk is low, especially when good hygiene and regular veterinary care are part of your routine. Knowing which parasites matter and how transmission happens can help you protect both your cat and your household.

Roundworms and hookworms	Tapeworms	Toxoplasmosis
These can occasionally affect humans through contact with contaminated soil, sand, or litter.	These are very rarely passed to people.	These are caused by Toxoplasma gondii, deserves special mention. Most healthy adults are not affected, but it can pose risks for pregnant people and those who are immunocompromised.
These cases are uncommon, but they’re one reason routine deworming and good litter box hygiene are recommended.	Infection usually requires accidentally ingesting an infected flea, which makes the risk extremely low in most homes — though small children tend to put everything in their mouths, which can slightly increase the risk.	The risk is tied to poor litter box hygiene — cats shed the organism only briefly, and it must sit in the litter for 1–5 days to become infectious. Cleaning the box daily and practicing good hand hygiene greatly reduces risk.

Simple preventive steps make a big difference:

Wash hands after cleaning the litter box or handling soil
Scoop litter daily and avoid touching your face during cleanup
Keep cats on veterinarian-recommended parasite prevention
Have someone else clean the litter box if you are pregnant or immunocompromised

If you have concerns about parasite exposure, for yourself or your cat, your veterinarian can help assess risk and recommend appropriate prevention strategies.

Parasite prevention for cats

Parasite prevention works best when it’s routine and consistent. Even indoor-only cats can be exposed through insects, shared spaces, or other pets in the household, which is why many veterinarians recommend year-round prevention rather than waiting for a problem to appear.

Most prevention plans involve monthly oral or topical medications that protect against common parasites like intestinal worms and fleas, and in some cases heartworms. The best option depends on your cat’s age, lifestyle, and local risks. Kittens often need different products and dosing, so early veterinary guidance is especially important.

Environmental steps also support prevention:

Regular vacuuming and washing bedding to reduce flea eggs
Prompt litter box cleaning to limit exposure to parasite eggs
Preventing hunting or contact with wildlife when possible

A few important safety reminders:

Never use dog flea or tick products on cats, as many contain ingredients that are toxic to cats
Be cautious with over-the-counter remedies or essential oils, which can cause serious reactions and may be ineffective
Always use parasite prevention exactly as prescribed for your cat’s weight and age

Your veterinarian can help you choose a prevention plan that balances effectiveness and safety, giving your cat protection without unnecessary exposure to medications they don’t need.

Get your kitten started on the right paw with our Optimum Wellness Plans^®. With unlimited office visits, 24/7 Pet Chat^™ (available in most states), and the option to customize with parasite prevention — you can help protect your kitten as soon as you bring them home. Explore kitten OWPs

How are cat parasites treated?

Treatment depends on the specific parasite involved, which is why an accurate veterinary diagnosis matters so much. While symptoms can look similar at home, different parasites require different medications, doses, and treatment timelines to resolve safely and effectively.

A Banfield veterinary professional holds a small grey tabby kitten

In general, treatment may include:

Intestinal parasites (like roundworms, hookworms, and tapeworms): prescription deworming medications given orally or topically, sometimes in multiple doses to fully clear the infection
Fleas and ticks: prescription topical or oral treatments that kill adult parasites and interrupt their life cycle
Mites: medicated ear drops or topical treatments prescribed by a veterinarian
Protozoal infections (such as Giardia or Coccidia): targeted medications along with supportive care to address dehydration or diarrhea

Heartworm disease in cats deserves special attention. Cats cannot receive the same heartworm treatment used for dogs, and there’s no safe way to eliminate adult heartworms once present. Because cats often carry very low numbers of worms, diagnosis can be challenging, which makes prevention and veterinary guidance especially important.

Using the wrong treatment or skipping professional care can be ineffective or even risky. Your veterinarian can confirm the parasite involved, prescribe the correct medication, and help prevent reinfection so your cat can recover comfortably and safely.

Important Notice: The information provided on this page is for informational purposes only and is not a substitute for professional veterinary advice. Always consult a veterinarian with any questions regarding your pet's health or medical condition. Never disregard or delay seeking professional veterinary advice based on information from this page.

Common questions about cat parasites

How do I know if my cat has worms?

Some cats show clear signs like worms in the stool or vomit, diarrhea, or weight loss, while others may seem completely normal. Because symptoms aren’t always obvious, a simple fecal test from your veterinarian is the most reliable way to get answers and peace of mind.

What do flea eggs or flea dirt look like?

Flea dirt looks like tiny black specks in your cat’s fur and will turn reddish-brown when placed on a damp paper towel. (It’s actually digested blood.) Flea eggs are much smaller, white, and easy to miss, which is why infestations can sneak up on even the most attentive owners.

Ready to protect your cat from parasites?

Parasites are common, but prevention can make a big difference. Schedule a visit with your Banfield veterinary team to build a plan tailored to your cat’s needs.

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