Do cats hurt when they have worms?
Don’t Ignore These Symptoms of Worms in Cats
Kelly has more than 12 years experience as a professional writer and editor.
Reviewed by Saleema Lookman, RVT
Saleema Lookman, RVT
First venturing into the freelance space in 2016, Saleema has since had case reports and peer-reviewed articles published in distinguished journals like The NAVTA Journal and Today’s Veterinary Nurse, as well as several articles published at various digital publications.
Updated April 20, 2022
It’s important to know the symptoms of worms in cats so you can identify these pesky parasites, then treat your feline friend. Symptoms associated with worms depend on the type of worm your cat has. You’ll notice some of the same symptoms appear with different types of worms, which is why a vet must identify the exact type of worms a cat has in order to provide the right de-worming treatment.
Signs of Roundworms in Cats
Roundworms (Toxocara cati, Toxascaris leonina) are one of the most common parasites with which your cat may come in contact. They are 3 to 6 inches long, are usually a milky white or tan color, and have tapered ends. Your cat passes them either through vomiting or in their stool, and they look like spaghetti.
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- What to Do if Your Cat Is Throwing Up Worms
Roundworm Symptoms
- Look pot-bellied
- Constantly feel hungry
- Stop eating
- Vomit (with or without worms in the vomit)
- Have sudden or chronic diarrhea
- Be less active than usual
- Have a dull coat
It is important to note that roundworms can be transmitted to humans and other animals in the household.
Cat Tapeworms Symptoms
Tapeworms (Dipylidium caninum, Taenia taeniaeformis) are very common in animals, especially those that have a flea infestation. Cats get tapeworms from ingesting fleas that are carriers of this parasite. These worms stick to the intestinal lining of the animal and feed on digested food.
You can easily see tapeworm segments, which the worm sheds and your cat will pass, with the naked eye; they are small and white in color. Dead segments of the tapeworm can be identified as tiny, rice-like pieces in your pet’s bedding. You will usually find them in your pet’s stools or stuck in the fur under and around a cat’s tail.
Tapeworm Symptoms
Symptoms of tapeworms include:
- Seeing small segments of worms in the fur on your cat’s rear
- Seeing worm segments in your cat’s stool
- Weight loss
- Constant hunger
- Diarrhea
- Scooting
Luckily, tapeworms are not easily transmitted to humans.
Signs of Hookworms in Cats and Kittens
Hookworms (Ancylostoma braziliense, Ancylostoma tubaeforme) are also a common parasite in felines, although they are difficult to see with the naked eye. They feed off the blood of the animal they have infested and can cause anemia. This can be fatal in felines, especially kittens. Adult cats may not exhibit any symptoms though they can still be infected with worms.
Hookworm Symptoms
Symptoms caused by hookworms include:
- Blood in the stool
- Dark, tarry stools
- Diarrhea
- Abdominal pain
- Weight loss
- Pale gums
- Weakness
Hookworms can be transmitted to humans by walking barefoot on infected ground.
Recognizing Stomach Worms in Cats
Stomach worms (Ollulanus tricuspis, Physaloptera spp.) live in a cat’s stomach. Ollulanus is rare in the United States but can still be found in stray cats and households or facilities that have multiple cats. Animals become infected with this stomach worm by ingesting the vomit of an infected animal.
Cats can become infected with the Physaloptera worm by ingesting crickets or cockroaches. It can also be obtained by eating a transport host, such as a rodent that has also eaten the infected cricket or cockroach.
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Stomach Worm Symptoms
Symptoms of Ollulanus and Physaloptera worms in cats include:
- Vomiting
- Weight loss
- No appetite
- Lethargy
- Dark, sticky diarrhea
These worms can be identified by a veterinarian through inspection of the infected animal’s vomit and stools.
Heartworms in Cats
Heartworms are seen more often in dogs than in cats. An animal gets the parasite through a bite from a mosquito. Generally, cats are not natural hosts of this parasite, but they can become infected. Unfortunately, there is not approved treatment for heartworms in cats, as the drug used to kill heartworms in dog is toxic to felines. The best way to protect cats from heartworm infection is prevention.
Heartworm Symptoms
Infected cats may show little or no signs of these invaders. However, as the disease advances, you may see symptoms including:
- Coughing
- Labored breathing
- Vomiting
- Lethargy
- Weight loss
- Poor appetite
- Sudden death
Heartworms cannot be transmitted to humans, but they can be fatal in cats. Talk to your vet about protecting your cat from this type of worm.
Know the Signs of Worms in Cats
The info provided here is not meant to replace professional veterinary diagnosis and treatment. While over-the-counter de-worming medications may work, they can cause stomach distress for your pet, and they may not kill the pests completely. For your pet’s health and safety, seek the advice of a veterinarian before beginning any de-worming program.
- Blood in Cat Stool: What You Need to Do Next
- Adopting Two Cats: Will They Get Along?
- What to Do if Your Cat Is Throwing Up Worms
Internal Parasites in Cats
This handout gives an overview of some of the internal parasites that can infect your cat. For more detailed information, refer to the separate handouts «Roundworm Infection in Cats», «Hookworm Infection in Cats», «Tapeworm Infection in Cats», and «Heartworm Infection in Cats».
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—>Are there different types of internal parasites or worms?
There are several types of internal parasites that cause problems in cats. These include roundworms (Toxocara cati and Toxascaris leonina), heartworm (Dirofilaria immitis), tapeworms (Dipylidium caninum, Taenia species, and Echinococcus species), and hookworms (Ancylostoma species).
Are these parasites dangerous to cats?
Intestinal worms can be a serious problem in young kittens. Hookworms can cause anemia and roundworms can lead to poor growth and development. Tapeworms can also accumulate in high numbers, leading to intestinal obstruction. In adult cats, however, intestinal parasites are only occasionally life-threatening. Debilitated animals, or those that have a weakened immune system, are more likely to experience severe intestinal parasitism and show clinical signs. Heartworm disease is a major life-threatening problem in dogs and is increasingly recognized as a threat to cats. Heartworm disease is transmitted by mosquitoes and can cause extensive damage to the heart and lungs.
«Heartworm disease is a major life-threatening problem in dogs and is increasingly recognized as a threat to cats.»
What will happen if my cat gets worms?
Roundworms
If a growing kitten is infected with a large number of roundworms, the worms can stunt the kitten’s growth, cause serious digestive upset, and result in excessive gas formation. These kittens often have a characteristic ‘pot-bellied’ appearance.
Roundworms are free-living in the intestines. They do not require an intermediate host to spread from cat to cat but can be transmitted by ingesting the eggs passed in the feces of an infected cat.
Hookworms
Hookworms are one of the most significant intestinal parasites of the cat. The hookworm is approximately ½” to 1″ (1-2 cm) long. It attaches to the small intestine lining, where it feeds on blood. As a result, hookworms can cause severe anemia in infected cats. The infective larvae can enter the host either by mouth or through the skin, particularly the feet. Eczema and secondary bacterial infection can occur due to irritation as they burrow through the skin.
Tapeworms
Tapeworms require an intermediate host, such as a flea, a bird, or certain species of rodents, to complete their lifecycle. In other words, your cat cannot get tapeworms directly from another cat or dog.
«. your cat cannot get tapeworms directly from another cat or dog.»
Dipylidium caninum, the most common tapeworm affecting cats, causes few problems in the adult cat but can cause digestive upset and stunting of growth in kittens. The intermediate host of Dipylidium is the flea; cats get tapeworm by eating an infected flea.
Taenia species of tapeworms usually infect adult cats and cause few problems. The intermediate hosts for Taenia species are small mammals such as rodents, rabbits, and some species of birds. Therefore, this parasite is most common in outdoor cats who hunt. Kittens are occasionally infected (mostly when they eat raw prey) and, in heavy infections, large numbers of tapeworms can cause intestinal blockage.
Echinococcus is important to be aware of because it is zoonotic, meaning it can infect humans. The adult tapeworm is tiny, only about ¼» (5-6 mm) long. Sheep and humans can act as the intermediate hosts for Echinococcus, with the immature forms of Echinococcus developing inside various organs of these species. Echinococcus is a risk to cats that live near sheep.
Heartworms
Heartworm disease is uncommon in cats but increasing in incidence, especially in certain areas of North America. Heartworms are spread by mosquitoes; a mosquito, when feeding on a cat, may inject heartworm larvae into the bloodstream. These larvae mature and ultimately travel to the heart, residing in the major vessels of the heart and lungs. Adult heartworms are large, reaching 6-14 inches (15-36 cm) long. They are primarily located in the heart’s right ventricle and adjacent blood vessels.
In the cat, symptoms associated with heartworm infection are non-specific. Heartworm disease may lead to coughing, rapid breathing, weight loss, and vomiting.
How are internal parasite infections diagnosed?
Hookworm and roundworm infections are diagnosed using a process called fecal flotation, where a small stool sample is mixed with a special solution that causes the eggs to float to the top of the solution. Tapeworm can be detected by observing segments (proglottids) on the feces or around the cat’s anus. Sometimes, these internal parasites are not discovered until clinical signs become present. For this reason, a fecal examination should be part of your cat’s routine annual health care program.
«. a fecal examination should be part of your cat’s routine annual health care program.»
Diagnosing a heartworm infection in cats can be difficult. Blood tests are the preferred method and include an antibody test, which can detect early stages of heartworm infection, and an antigen test, which may detect the presence of adult worms (rare) later in the course of the disease. Occasionally, a cat infected with heartworms will die suddenly and the diagnosis will be made on a post-mortem examination.
How can I prevent or treat these parasites?
Prompt treatment should be started when any intestinal parasites are detected. Periodic routine deworming may be appropriate for cats at risk for re-infection or with regular outdoor access. Controlling fleas will prevent infection of certain types of tapeworm. There are excellent heartworm preventives now available for cats, making prevention of heartworm disease safe and easy. Many heartworm preventives also protect against certain intestinal worms. Speak with your veterinarian about the most appropriate parasite control program for your cat.
Are there other internal parasites that can affect my cat?
Other internal parasites that affect cats include whipworm, lungworm, coccidia, and giardia. See handouts “Coccidiosis in Cats” and “Giardia in Cats” for more information on these topics.
