It can be unnerving to think about the possibility of worms in cats, but understanding the different types of worms that they can get and how to treat them is essential for keeping your feline friends healthy. In this blog article, we will discuss the different types of worms affecting cats - from roundworms to tapeworms - as well as the symptoms and treatment options that you should know about if you suspect your cat may have a worm infection. So if you’re worried about worms affecting your cat, read on!
A Look at the Different Types of Worms in Cats
Cat owners must be aware of the various worm varieties that may affect their cats. Each type of worm has a distinct lifespan and method of transmission, which might have an impact on the preventative and therapeutic measures you should take. Let's examine these various worm species in more detail.
- Roundworms (Toxocara cati): Roundworms are the most common type of worm in cats. The cat's intestines are home to these lengthy, spaghetti-like worms. Cats can contract roundworms by eating infected rodents, infected birds, or contaminated cat excrement. Roundworms are also transmitted to kittens through the mother's milk.
- Tapeworms (Dipylidium caninum or Taenia spp): Tapeworms are amongst the most common types of worms in cats. Flat, segmented worms called tapeworms stick to the cat's intestines. Cats typically contract tapeworms by eating an intermediate host that is home to the tapeworm larvae, such as a flea or rodent (e.g. mouse). If you notice small rice-like bits on your cat's stool or beneath its tail, check thoroughly for fleas.
- Whipworms (Trichuris): Whipworms are worms in cats that reside in the large intestine and adult whipworms can produce up to 100 eggs per day. Whipworms in cats feed on blood and the intestinal lining and transmission occurs via a contaminated environment. Whipworm eggs are very infectious and highly resistant to extreme temperatures and desiccation.
- Hookworms (Ancylostoma tubaeforme): Hookworms are small worms in cats and firmly attach to the walls of the intestine and feed on blood. Transmission can occur in a variety of ways such as by ingesting larvae from the environment, ingesting hosts that carry the parasite and in some cases, larval penetration into the skin. Due to their small size and ability to attach themselves firmly to the intestinal wall, adult hookworms are difficult to detect in feces. They live and mate inside the intestines.
- Heartworms (Dirofilaria immitis): Unlike the other types of worms, heartworms live in the major blood vessels around the heart and lungs in cats. Cats get heartworms through the bite of an infected mosquito. Although heartworms are less common in cats than in dogs, an infection is often very serious.
- Lungworms (Aelurostrongylus abstrusus): Lungworms as the name suggests, are worms that live in the lung tissues of cats. Cats usually become infected with lungworms through ingestion of hosts including mice, frogs, lizards, snakes and some birds.
Symptoms of Worms in Cats
While symptoms of worms in cats can vary depending on the type of worm infestation, there are some common signs that you should look out for. Remember, early detection is key to ensuring your cat gets the treatment they need as quickly as possible.
Intestinal worms in cats such as roundworms, whipworms, hookworms and tapeworms will cause gastrointestinal symptoms. Common such symptoms may include vomiting and/or frequent hairballs, diarrhea, straining to defecate, appetite changes (increase or decrease) and weight loss. Cats that have a tapeworm infection may also show signs of scooting their bottom along the ground and have rice-like structures (tapeworm segments) attached to their fur.
Apart from tapeworms, you may or may not notice worms in the stool. Roundworms, whipworms and hookworms live and reside in the intestines. When you see worms in the stool of cats, the intestinal tract is likely overloaded with worms and they are simply being forced out. It is not unusual for cats with worms to vomit up the worms.
Cats with heartworm infection often display chronic, yet significant symptoms such as coughing, difficulty breathing, weight loss and lethargy.
With lungworm infections in cats, cats that have a large number of lungworms may display coughing, sneezing, difficulty breathing, and increased respiratory rates/panting. Symptoms may not be noticeable in the case of minor lungworm infestations.

How are Worms in Cats Diagnosed?
If you suspect your cat has worms, it's important to take them to your veterinarian for a proper diagnosis. Here's how veterinarians typically diagnose worms in cats:
- Fecal Floatation: This is the most common method used to diagnose worms in cats. Your veterinary team will take a sample of your cat's feces and examine it under a microscope to look for the presence of worm eggs. This test is effective for diagnosing most types of worms, including roundworms, whipworms and hookworms. It is uncommon to see tapeworm eggs with a routine fecal floatation.
- Visual Inspection: In some cases, worms or worm segments may be visible in your cat's feces or around its anus. Tapeworm segments, for example, can often be seen as small, rice-like pieces in your cat's feces or stuck to the fur around its tail.
- Blood Tests: For some types of worms in cats, such as heartworms, a blood test is necessary to make the diagnosis. Heartworms are diagnosed by detecting specific antigens (proteins) produced by adult female heartworms in the cat's blood.
- Baermann Test: This is a special type of fecal test used specifically to diagnose lungworms. This test is the least invasive, most affordable, straightforward, and most sensitive way to detect lungworms in cats. It involves using warm water to stimulate the larvae to leave the fecal sample, making them easier to detect under the microscope.
What is the Treatment for Worms in Cats?
When your cat is diagnosed with worms by your veterinarian, they will advise a course of therapy that is suitable for the particular type of worm that your cat has.
Intestinal Deworming Medications: There are a variety of deworming medications available to treat intestinal worms in cats. Common dewormings include pyrantel, milbemycin, moxidectin and fenbendazole. Praziquantel-based medication should be used to treat tapeworm infections in cats. Fortunately, many products available will combine multiple deworming ingredients to achieve broad-spectrum control of intestinal worms in cats. As these dewormers will not kill eggs or early larval stages, it is important to have repeated doses, typically every 2 weeks for a few treatments to ensure complete eradication.
Heartworm Treatments: Treating heartworms in cats can be more complex and requires a careful approach. Because the death of adult heartworms can cause a severe inflammatory response, treatment often involves managing the symptoms and using medications to kill the immature stages of the worm and prevent new infections.
Recommended Preventative Deworming Strategies for Cats
For kittens, we recommend starting a deworming strategy at 6 weeks of age. There is an incredibly high risk that the kittens have contracted worms from their mother's milk. We recommend that kittens get routinely dewormed every two weeks until they are 12 weeks old, then monthly until 6 months of age.
For adult cats, we recommend a routine deworming strategy based on risk and lifestyle. We do not routinely deworm indoor cats but we do recommend a stool sample check once yearly at their annual health exam. For outdoor cats, we recommend deworming once monthly or every other month as needed.
Ultimately, it's important to consult with your veterinarian regularly when it comes to deworming your cat. They can help you create an individualized deworming plan that takes into account the lifestyle and risk factors of your cat.
The Companion Animal Parasite Council (CAPC) has great information available on current recommendations and guidelines when it comes to the treatment and prevention of the various worms in cats.
Human Health Risk
While our focus is often on the health of our feline friends, it's important to note that some types of worms can also pose a risk to human health. Cats can transmit certain worms like roundworms and hookworms to humans. This usually happens when a person accidentally ingests worm eggs (for example, by touching contaminated soil or cat feces and then touching their mouth). Fortunately, good hygiene practices, such as washing hands regularly and avoiding direct contact with cat feces, can significantly reduce the risk of transmission.
It is also important to note that some species of tapeworm can affect people such as the Dipylidium tapeworm. Humans, especially children, can become infected with tapeworms if they accidentally ingest an infected flea. This can happen when a child has close contact with an infected pet or contaminated environment.
In our comprehensive exploration of parasitic worms in cats, we've identified several types that can affect our furry friends, including roundworms, tapeworms, hookworms, heartworms, and lungworms. We've learned to spot the telltale signs of these infections, such as weight changes, appetite shifts, digestive disturbances, coat changes, abdominal enlargement, and unusual lethargy. We've emphasized the crucial role of professional veterinary intervention for accurate diagnosis and effective treatment, along with the importance of regular deworming schedules for different life stages of cats. We've also touched upon the risk of certain worms, like Dipylidium tapeworms, being transmitted to humans, underlining the significance of maintaining good hygiene practices. In the end, the well-being of our cats hinges on early detection and intervention, consistent veterinary care, cleanliness, and preventative measures, ensuring our feline companions lead comfortable, worm-free lives.