How to treat worms in cats at home

Written by Small Door's medical experts

Discovering your cat has worms can be shocking and upsetting. Whether they’re external or internal, these parasites can wreak havoc on your cat’s health. But with proper diagnosis and treatment, worms in cats can be effectively treated and eliminated.

In This Article

Here’s a list of the most common worms found in felines:

• Roundworm: These are the most common intestinal parasites found in cats; they’re also visible to the naked eye. Roundworms measure anywhere between three to five inches long and look like spaghetti noodles. They steal nutrients from the food your cat ingests. The worms then produce eggs, which are eliminated through the feces. On occasion, you may be able to see the roundworms moving around in your cat’s poop or vomit.

• Tapeworm: Tapeworms, another internal parasite, are flat and ribbon-like inside the intestine, but segments of the worms can resemble small grains of rice or sesame seeds in your cat's stool. Your cat may contract tapeworms by ingesting a flea infested with tapeworm eggs, either while grooming themselves or by eating an infested bird or rodent. The worm will only come to maturity inside the intestine. Pieces of the worm then break off and are expelled through the feces. You may be able to spot them in your cat’s feces or on the fur near the anus, but in some cases they are passed sporadically, meaning they may not always be found during a fecal examination

• Hookworm: These small internal parasites get their name from the hook-like teeth they use to attach themselves to the lining of the intestine, where they feed off your cat’s blood. Cats contract hookworms either by ingesting them directly, from larvae that penetrate their skin, or while still in utero from their mother. The larvae first make their way to the lungs before settling in the intestines, where they grow into adult worms. Hookworms are the most harmful of the internal parasites because of the possibility of intestinal bleeding. Fortunately, this type of parasite is less common in cats than other types of worms. Hookworms are not often visible to the naked eye, but because anemia is a primary symptom, you may notice signs such as pale gums/nose, and lack of energy.

• Heartworm: Heartworms are potentially deadly parasites that infest the heart, blood vessels and lungs. They’re transmitted through the bite of infected mosquitos. Unfortunately there is no cure for heartworm in cats, so monthly preventatives are the only form of protection.

• Lungworm: Lungworms are contracted when a cat drinks contaminated water or hunts and consumes birds or rodents infested with lungworm larvae. Once the larvae make their way through your cat’s intestines, they travel to the lungs where they develop into adult worms and lay their eggs. Lungworms are expelled either by being coughed up or passed through your cat’s feces. Lungworms often go undiagnosed because the symptoms—in the form of respiratory problems—are similar to those caused by other conditions like bronchitis or pneumonia. Fortunately, lungworm is relatively uncommon.

• Whipworms: Whipworm infections in cats can be serious, but are thankfully rare in North America. These parasites are contracted when a cat ingests anything containing their eggs, which may be found in food, water, soil, infected feces, and animal flesh. Whipworm eggs can survive in the environment for up to 5 years, take 11 weeks to mature in the body and can survive in the host for up to 16 months. Cats infected with whipworms may show signs of weight loss, digestive or intestinal issues, and bloody diarrhea.  

• Stomach worms: Stomach worms are transmitted through the vomit of an infected cat, and they’re most common in free-roaming cats or those from multi-cat households. Symptoms of stomach worms include loss of appetite, chronic vomiting, weight loss and malnutrition, though infected cats may remain asymptomatic. Luckily, stomach worms are easily treatable.   

• Bladder worms: Bladder worms are not very common in cats and are rarely detected since they have no clinical signs. Severely infected cats may exhibit signs of urinary tract infections or diseases. Bladder worms are expelled through your cat’s urine.

• Liver flukes: Liver flukes in cats typically affect the small intestine, liver, pancreatic duct, and bile duct. The cat liver fluke lives in water and infects cats through a secondary host. For example, the liver fluke first infects an intermediate host, commonly a land snail. That snail is then eaten by a lizard or frog which becomes the liver fluke's secondary host. This second intermediate host is then ingested by a cat, which results in the cat becoming infected with liver flukes. The natural environment for cat liver flukes is warm subtropical areas, such as Florida and Hawaii. 

You may also have heard of ringworm. Despite its name, ringworm is not actually a worm. It’s a fungal disease that affects the skin and hair of a cat.

In this remainder of this article, we’ll mostly focus on the most common intestinal worms: roundworms, tapeworms and hookworms.

Both indoor and outdoor cats, old and young, can contract worms. Adults can contract worms from contaminated feces, fleas, or rodents, while younger kittens can be exposed to worms through nursing.

The following symptoms are signs that your cat may be infested:

• Visible presence: For many cat owners, the first sign will be a visible presence of worms. You may see whole worms, parts of worms or worm eggs in your pet’s stool or vomit. Worms or eggs can also sometimes migrate to a cat’s anus, getting stuck in the fur.

• Change in coat: If your cat is infested with a parasite, their fur may appear dull, rumpled or clumped due to lack of nutrients or dehydration.

• Change in color of gums: The gums of a healthy cat should be nice and pink, but if they appear pale or white, your cat may be experiencing anemia, due to the worms.

• Vomiting: Vomiting is a common occurrence in cats, but if it’s happening more frequently than usual, worms could be the culprit.

• Change in stool / bowel movements: Dark, tarry stool indicates the presence of blood, potentially from hookworms. Worms in the gut can also cause diarrhea.

• Increased appetite despite weight loss: As the worms deprive your cat of vital nutrients, they need to take in more food in order to try to maintain their body condition.

If you notice any of the above signs, it’s important to have your cat examined by your vet immediately.

Although the different types of worms vary in how they are contracted, there are a few main ways that cats tend to get worms. These include being passed on through feces, ingesting an infected host (such as a bird, rodent, reptile, or insect), and cats with fleas grooming themselves and swallowing the fleas.

Can cats get worms from dogs?

Yes, cats can contract worms from dogs. This typically happens when a cat ingests feces from a dog that is infected with worms.

Are worms painful for cats?

Worms can be painful for cats, and in particular those with heavy parasite loads or related issues may become very unwell.Gastrointestinal symptoms such as vomiting, diarrhea and cramping can cause discomfort, and as certain worm larvae travel through the cat’s internal organs, they can also cause inflammation of the affected tissues and further discomfort.

While some worms can be seen by the naked eye, others must be diagnosed with fecal testing. Your veterinarian will ask you to bring in a stool sample, which will be placed in a solution that allows the parasite eggs to separate from the feces and float to the top.

Next, a drop of the sample is placed on a slide and examined under a microscope to determine the exact type of worm infesting your cat. A physical exam, along with blood work, may also be carried out to get a complete picture of your cat’s health.

Because the lifecycle of each parasite is different, it’s important to know exactly the type of worm infesting your cat. This will determine medication, treatment, and follow-up care. After treatment, your cat will likely need another fecal exam to ensure the worms have been wiped out.

Thankfully, most intestinal worms in cats are easily resolved with either a single dose of dewormer or a short course of deworming medication that your vet can prescribe and administer. Certain worms (including hookworms and lungworms) can be more stubborn to resolve, resulting in slightly longer treatment courses of intestinal dewormers.

Yes, humans can get worms from cats if they come in direct contact with infected feces or soil. This tends to happen when people are gardening without gloves, walking barefoot through infected soil, or if children are playing in a sandbox that has infected feces from cats. The best way to prevent this from happening is to practice good hygiene.

The best way to treat worms in cats is with deworming medication, to kill both the larvae and adult worms within your cat’s intestines. In many cases, dewormers may be given in multiple doses to interrupt the life cycle of the intestinal parasite. Make sure to follow your vet’s instructions for dosage amounts and when to administer them. In many cases, the second dose is used to kill any worms that might have hatched after the first dose was administered.

Depending on the type and severity of infection, worm infestations that remain untreated can lead to serious health issues for your cat – including malnutrition, severe anemia, and intestinal obstructions – which can become life-threatening. This is why it’s always important to treat worm infestations as soon as possible.

Once your cat has been treated for worms, it’s important to continue to be proactive about keeping her safe. Adhering to a strict year-round flea prevention regimen can help reduce the risk of tapeworm infection, since fleas carry worms.

Equally, if your cats are avid hunters and especially if they spend time both indoors and outdoors, preventative deworming every 3 months can help eliminate any intestinal worms before they can become a large burden for your pet. Finally, pay attention to your cat’s litter box, keeping it fresh and clean on a daily basis.

There are some worms that can be harmful to humans. In order to protect yourself, along with your cat and any other pets, clean up cat feces immediately, wash your hands, and if possible, wear gloves whenever cleaning the litter box.

There are many different types of worms that can infest cats, so be aware of the signs and symptoms. Immediate treatment will not only help prevent the infestation in your cat from becoming worse, but it will also help protect the other pets (and humans) in your household. Discovering that your cat has worms may be disturbing, but with effective treatment from your vet, your cat will be worm-free before you know it!