Hepper is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

How Do Indoor And Outdoor Cats Get Worms?

Dean Eby

By Dean Eby

siamese lynx point_Seattle Cat Photo_Shutterstock

Just the thought of parasites living inside of your feline can bring horror to an average pet owner. Gastrointestinal parasites are rather common though, and if you have a cat, it’s pretty likely that you’ll deal with them at some point. More commonly known as worms, these parasites are all around, and they’re quite easy for your cat to contract.

You might think that if you have an indoor cat it should be safe from such parasitic infections, but that’s simply wishful thinking. The truth is, whether your cat spends its time indoors or out, it’s still susceptible to worms. Luckily, worms aren’t terribly dangerous, and treating them isn’t difficult. You can even prevent them with proper vaccinations, all subjects that we’ll be covering in this article. But first, let’s talk about the types of worms your cat is likely to contract.

Three Types of Worms that Cats Contract

siberian cat_claudia125_Pixabay
Image Credit: claudia125, Pixabay

There are many types of worms and lots of different gastrointestinal parasites, but the following three are by far the most common ones for a cat to suffer from.


Tapeworms are multi-segmented parasites, and each segment contains its own set of reproductive organs. These worms are long and flat, and they attach to your cat’s intestines. Often, cats that are infected with tapeworms show no symptoms. The condition is usually noticed when the pet’s owner finds small white pieces in the cat’s poop or where the cat sleeps. These worms are usually contracted by ingesting an animal that was infected.


roundworms_Rattiya Thongdumhyu_Shutterstock
Image Credit: Rattiya Thongdumhyu, Shutterstock

In cats, roundworms are the most common worms. They feed on your cat’s blood while living attached to its intestinal lining. As the parasites reproduce, their eggs pass through the cat and hatch into larvae in the cat’s feces and in the soil where the feces were deposited.


Much like roundworms, hookworms will attach to the lining of your cat’s intestines and feed on its blood. They also reproduce inside your cat’s body. The eggs of the hookworm will be excreted by the cat, which allows them to propagate in the fresh air and reinfect your feline through contact with the contaminated soil.

Related Read: How Cats Get Ringworm (And How To Prevent It)

What Cats Are Most Susceptible to Worms?

kittens in grass_Jan Mallander_Pixabay
Image Credit; Jan Mallander, Pixabay

All cats can get worms, but some cats are more susceptible to them than others. For instance, kittens are at a much higher risk than older cats. While drinking their mother’s milk, parasites can be passed from mother to kitten. Outdoor cats also tend to be at higher risk for worms than indoor cats, simply because they have far more opportunity for exposure. But even indoor cats can easily be exposed to such parasites from other pets or contaminated items. And any animals that are regularly in contact with others, such as multiple pets in the same household, are at increased risk of parasitic infection.

What Are the Symptoms of Worms in Cats?

Cat vomiting_Nils Jacobi_Shutterstock
Image Credit: Nils Jacobi, Shutterstock

You won’t always see the symptoms of a worm infection. Depending on the parasite and the feline, there might not be any noticeable symptoms other than pieces of the worms appearing in your cat’s feces and on its rear end. But many times, your cat will start to suffer some more obvious effects, and if you know what to look for, you might be able to recognize these effects as signs of a parasite.

Some of the most common symptoms of worms include:

  • Your cat is dragging its butt on the floor
  • Diarrhea
  • Vomiting
  • Bloating of the stomach
  • Lack of energy
  • Its coat is becoming coarse
  • Sudden and/or rapid weight loss

How Are Worms in Cats Treated?

Credit: Ermolaev Alexander, Shutterstock

Treating worms in felines is rather simple, but the treatment is usually dependent on what type of worm your cat has contracted. Over-the-counter deworming medications are available, and many vets will recommend them. However, if you want to be certain your treatment is effective, it’s best to let a veterinary professional determine the best course of action. They could prescribe a powerful dewormer that’s given through injection, pill, oral liquid, or topical medication.

How Are Worms in Cats Prevented?

The best way to prevent your cats from getting worms is to provide year-round worm prevention medications. Your vet can recommend the best one for your cat, but these generally only need to be applied once or twice per year. Even if you don’t think your cat is at much risk of getting worms, a simple vaccination can help ensure that the risk is as minimal as possible.

Stray cat_Dimitris Vetsikas, Pixabay
Image Credit: Dimitris Vetsikas, Pixabay

Additionally, you’ll want to do your best to keep your cat’s living area clean and sanitary. Each cat should have its own litter boxes, which need to be cleaned and disinfected every week. You should also have a stool analysis completed as part of your cat’s regular exams, as this can help to catch any instances of parasites early on, preventing the needless suffering of your furry friend.

7 Ways Indoor and Outdoor Cats Get Worms

There are many ways that cats can get worms. Whether they’re primarily indoor cats or they’re spending all their time outdoors, your cat can get infected in many ways, but the following seven are the most common and likely means of contraction.

1. Time spent outdoors

chartreux cat in grass_Piqsels
Image Credit; Piqsels

Obviously, most of the parasites are living outside, so, the more time your cat spends outside, the more likely it is to contract a parasite. Other animals have contracted these parasites, and many of the parasitic offspring lie on the ground in wait. If your cat happens to walk over an infected area or lays down for a nap where there are parasites, then the infection will easily take place.

2. Open windows and doors

american shorthair cat lying_Kari Dickinson_Pixabay
Image Credit: Kari Dickinson, Pixabay

It might seem ridiculous to think that parasites can simply blow into your home on a breeze through an open window, but it can actually happen. Granted, this isn’t the most likely manner of infection, but it’s still a viable possibility.

3. A visit to a high-risk area

american shorthair cat outdoor_Piqsels
Image credit: Piqsels

One of the most common ways that your cat can contract a parasite is through contact with other animals. This is accentuated when your cat has visited a high-risk or high-traffic area, including places like veterinarian offices, the kennel, or a cat training facility. Anywhere that other animals spend time is a place with a high risk of infection. If any of those other pets were infected, then the parasites are now in the area, waiting to infect another unwitting victim.

4. Eating contaminated animals

cat in garden_Piqsels
Image credit:Piqsels

Cats are obligate carnivores and adept hunters. They love to hunt down and consume small mammals. Generally, it’s not much of a problem, but if your cat happens to hunt down an infected animal and consume it, then the parasites will be transferred to your cat.

5. Contaminated intruders

siberian cat indoor_Joanna Gawlica-Giędłek_Pixabay
Image Credit: Joanna Gawlica-Giędłek, Pixabay

Your cat doesn’t even have to eat the animal to get parasites from it. Let’s say, for example, that a rat made its way into your home. Even if your cat can’t find the rat, if it’s infected with a worm, that little rodent is releasing loads of parasites into the house through its feces, which can easily infect other household pets.

6. Contamination you tracked in

maine coon cat_Michelle Raponi_Pixabay
Image Credit: Michelle Raponi, Pixabay

It doesn’t even take another animal to infect your feline. You might even step on a parasite and unknowingly track it into your home on your shoes or clothes. Once in your home, the parasite sheds from your clothes to the floor, where it waits to attach to a passerby, and your cat makes the perfect host.

7. Another animal in the household

As you can see, getting contaminated from other sources is easy. If you have a multi-pet household, then your cat could get contaminated by one of the other pets. Maybe your dog was playing outside and rolled in a patch of dirt that contained tapeworm larvae. When it comes back in, those larvae can easily infect your cat, creating an entire household of infected pets!


Worms are gastrointestinal parasites that live in your cat’s body and make it sick. You might not notice any symptoms, but you should definitely look out for little white particles in your cat’s stool. If you think your cat has worms, the vet should be able to check for you. Luckily, treatment is simple; just use a deworming medication. You can even prevent worms in the first place with proper yearly vaccination.

Even if your cats get worms, it’s not the end of the world. Rather, it’s pretty common, and it’s easily treatable. Just try to keep your cat’s living area sanitary and get regular checkups for your cat so you can catch the infection early. Remember, there are many ways your cats can get infected, so, even if your cat spends all its time indoors, it’s not immune to worms.

Featured Image Credit: Seattle Cat Photo, Shutterstock

Related Articles

Further Reading

Vet Articles

Latest Vet Answers

The latest veterinarians' answers to questions from our database