Last Updated: 23/12/2025
Worms in Cats: Signs, Types, and Treatment Guide
Are you worried about parasites? Our expert guide covers everything Australian cat parents need to know about intestinal worms, heartworm, and lungworm. Discover how to spot the signs, protect your family, and choose the right treatment for your pet.
Author: Dr Carla Paszkowski BVSc (Hons)
Reading Time: 16 minutes - medium read
While we’d all prefer to think of our cats as pristine indoor hunters of nothing more than toy mice, the reality is that intestinal parasites are a common part of feline life in Australia. Whether it's a kitten inheriting roundworms from their mother or an adult cat picking up a flea tapeworm during a grooming session, these "uninvited guests" are more common than you might think. Because some of these parasites can also affect human family members, staying on top of a preventative schedule is the best way to ensure your whole household stays happy and healthy.
How do cats get worms?
Cats most commonly contract worms after coming into contact with parasite eggs or infected faeces. Depending on the species of worm, cats may also catch worms:
- From their mother's milk
- Soil contaminated with faeces
- Fleas
- Hunting prey animals
Can indoor cats get worms?
Yes, they certainly can! Worm eggs can hitch a ride into your home on the soles of your shoes or via soil on pot plants. Roundworms and tapeworms can also be transmitted to cats through the consumption of undercooked or raw meat. Additionally, indoor cats can catch tapeworms if they hunt a stray flea or a rogue mouse that has made its way inside, or lungworms from an infested snail or slug. Mosquitoes, which carry heartworm, also don't respect "indoor-only" boundaries.
Read more in our article How Do Cats Get Worms?
Common types of worms in Australian cats
In Australia, there are three main types of worms your can cat can get; intestinal worms, heartworm and lungworm.
Intestinal worms
Worms that live in the gastrointestinal tract include roundworm, hookworm and tapeworm.
Roundworm
Roundworms are the most common intestinal parasite in cats. A single female adult roundworm can shed up to 200,000 eggs per day in the faeces of infested cats, and these eggs can survive in the environment for several years.
- What they look like: Typically creamy white or pale brown in colour and have a spaghetti-like appearance. They can range in size from a few millimeters to several centimetres long.
- How they spread: Cats can become infested with roundworm in various ways; through ingesting worm eggs from the soil, generally through normal grooming; consuming a prey animal, often a rodent, carrying worm larvae; nursing from an infected mother cat (a common route of transmission for kittens)
- What happens: Larvae is released from the egg in the small intestine after ingestion, migrates through the liver, heart and lungs, is passed up the trachea, coughed up and swallowed. The parasite then matures in the small intestine.
- Signs to watch for: Failure of kittens to grow normally, coughing, vomiting, pot-belly.
Hookworm
These nasty critters can inflict damage to the intestine where they attach and feed on the cat's blood. In extreme cases this blood-feeding parasite can lead to fatal blood loss, particularly in young kittens.
- What they look like: Small (1-2cm), thin worms with hook-like mouthparts. They are usually whitish or reddish-brown and are difficult to see with the naked eye.
- How they spread: Cats can become infested with hookworm in various ways; through ingesting the larvae in the environment; consuming a prey animal, carrying worm larvae in their tissues; larval penetration of the cat's skin.
- What happens: Larvae which penetrate the skin, as well as some that are ingested and penetrate the mucosa of the gut, migrate via the bloodstream to the lungs, are passed up the trachea, are coughed up and swallowed. The parasite then matures in the small intestine. Alternatively, ingested larvae may remain in the gut and mature to adults in the small intestine.
- Signs to watch for: Failure of kittens to grow normally, pale gums, weakness, lethargy, pot-belly, poor hair coat.
Tapeworm
The worms reside in the cat's gut and feed off the nutrients in there.
- What they look like: Flat and segmented, resembling grains of rice or small flat cucumber seeds. The segments may sometimes be seen moving near the anus or in the cat's faeces.
- How they spread: Cats become infested with tapeworm when they ingest an intermediate host infested with these parasites. The type of intermediate host varies with the different tapeworm species. Dipylidium caninum (the flea tapeworm) infestation occurs when cats ingest an infested flea during grooming; Taenia taeniaeformis (the cat tapeworm) infestation occurs when cats prey on and consume infested rodents or birds; Spirometra erinacei (the Zipper worm) infestation occurs when cats eat infested fish, reptiles or amphibians.
- What happens: Ingested larvae remain in the gut and mature to adults in the small intestine.
- Signs to watch for: Some cats may display no symptoms at all but others may exhibit mild signs of infestation, such as irritation and itchiness around the anus. Vomiting, diarrhoea, weight loss, inappetance, and lethargy are possible with Spirometra.
Read more in our article Tapeworms in Cats
Heartworm
Unlike dogs, cats are not the natural host of heartworm; however they can still contract the infection.
- How they spread: Cats can become infested with heartworm if bitten by an infected mosquito.
- What happens: Larvae mature in the muscles, fat or subcutaneous tissues, then move into the bloodstream and try to find the heart. As the worm is designed to navigate inside dog vessels, it can get 'lost' and end up in other places - such as the cat's lungs. The highly reactive feline immune system then attacks these immature worms. While the worm won't reach maturity, the immune reaction itself can cause significant damage to the surrounding tissue, especially the lungs.
- Signs to watch for: The cat's effective immune system usually fights the infection. Many cats won't show symptoms however if symptoms do arise, they may include coughing, lack of appetite, or weight loss. Unfortunately in some cats the first sign that may be seen is sudden death.
Read more in our article Heartworm Facts.
Lungworm
- How they spread: Cats ingest larvae when they hunt and consume an animal, such as a rodent or bird, that has ingested an infected mollusc (snails, slugs). However, cats can also become infected through consuming infested molluscs directly. Therefore, outdoor cats with hunting tendencies face the highest risk of contracting this parasite.
- What happens: Larvae migrate from the gastrointestinal tract via the liver and venous circulation into the bronchioles and alveolar ducts, where they moult and mature into adults.
- Signs to watch for: While some cats can live with a high worm burden, others may exhibit respiratory signs like coughing, wheezing and breathing difficulties.
Less common species
Liver flukes (Fasciola hepatica)
These are parasitic flatworms that target the liver. While rare in Australian cities, they are sometimes found in rural areas where cats might explore around dams or paddocks.
- How they spread: Cats ingest larvae by drinking contaminated water or eating raw fish, snails, or water plants.
- What happens: Larvae move from the gut to the liver, where they mature and can cause damage.
- Signs to watch for: Jaundice (yellowing of the gums or skin), weight loss, and lethargy.
Bladder worms (Capillaria feliscati)
These roundworms are very rare in Australia, as they prefer much colder climates. Unlike most worms, these reside in the kidneys and urinary tract.
- How they spread: Cats usually catch these by eating raw fish or freshwater crustaceans (like crayfish) that carry the parasite.
- What happens: The larvae travel through the body to the kidneys, where they can cause inflammation and infection.
- Signs to watch for: Blood in the urine, straining to pee, or abdominal pain.
Keeping your feline friend safe from these less common parasites is quite straightforward:
- Skip the raw fish: Always cook fish thoroughly before serving it to your cat.
- Fresh water only: Prevent your cat from drinking from stagnant ponds, puddles, or dams.
- Stay protected: Keep up with a regular, high-quality deworming schedule.
Recognising the symptoms of worms in cats
Common signs of intestinal worms:
- Diarrhoea (sometimes with blood)
- Worms, or worm segments, visible in your cat's stool or around anus
- Weight loss
- Distended (pot-bellied) tummy
- Vomiting or regurgitating
- Weakness
- Anaemia
- Dull coat
- No signs (many infected cats may not display any symptoms)*
*It is important to note that your cat might not show any symptoms at all, and evidence of worms may not always appear in their faeces. In certain rare instances, your cat may actually vomit up a worm - in which case it's advisable to take the expelled worm to your veterinarian for identification. You may also spot worm segments in the faeces. However, the most conventional method of diagnosing intestinal worms is by identifying worm eggs in the faeces which is done through faecal testing by your veterinarian.
The best worming treatment and prevention for cats
Treatment involves administering a dewormer to your cat. Regular treatment with a vet-recommended worming product is essential to help keep your cat worm-free, as they will continually be at risk for reinfection due to their natural behaviours of roaming, grooming, and hunting.
It's also vital to treat your cat for fleas, because fleas carry and transmit tapeworm. When a cat ingests a flea infected with tapeworm larvae, the larvae can develop into adult tapeworms within their intestine. Grotesquely, the same can occur inside your intestines!
*It is important to be aware that some worming products do not kill hydatid tapeworm. Tapeworm is large and more difficult to kill than smaller worm species, requiring a specific medication called Praziquantal. The selected products kill all important worm species, including tapeworm.
Vet picks
Protects against: Fleas, ticks, heartworm, roundworm, hookworm, lungworm and tapeworms (excluding Spirometra)
Protects against: Roundworm, hookworm, lungworm and tapeworms (excluding Spirometra)
Protects against: Roundworm, hookworm, heartworm and tapeworms (excluding Spirometra)
Protects against: Roundworm, hookworm and tapeworms (excluding Spirometra)
For more parasite protection recommendations read Which Flea and Worming Product Does Your Cat Need?
Can humans catch worms from cats?
Yes, humans can potentially catch certain types of worms from cats. These parasitic infections are known as zoonotic diseases, meaning they can be transmitted from animals to humans. Some common worms that can be transmitted from cats to humans include hookworm, roundworm, and tapeworm. Each worm is spread in a different way, which are outlined below.
How do humans catch different types of worms from cats?
- Roundworms (Toxocara spp.): Roundworm eggs shed in the faeces of infected cats can contaminate the environment. Humans, particularly children, can accidentally ingest these eggs from contaminated soil, sand, or surfaces, leading to toxocariasis. Symptoms in humans can include fever, abdominal pain, coughing, and in severe cases, organ damage.
- Hookworms (Ancylostoma spp and Uncinaria spp.): Hookworm larvae can penetrate the skin of humans upon direct contact with contaminated soil or sand. This can lead to skin irritation and the development of a condition known as cutaneous larva migrans, which presents as itchy, raised tracks on the skin.)
- Tapeworms (Dipylidium caninum and Taenia spp.): Humans can become infected with tapeworms by ingesting fleas infected with tapeworm larvae. Cats can acquire tapeworms by ingesting infected rodents or grooming themselves after flea infestations. In humans, tapeworm infections may cause abdominal discomfort and, in some cases, the passage of tapeworm segments in the stool.
The lesson here is to worm your cat regularly, and wash your hands after petting or changing your cat's litter tray. It's also best not to let your children play in a sandpit or in the dirt if stray cats roam the area!
Worms might be gross, but they don't have to be a major health hurdle. By maintaining a regular parasite prevention schedule and keeping an eye out for any changes in your cat's health, you can easily stay ahead of these parasites. Remember, a worm-free cat is a much happier (and more comfortable) companion!
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History
Our experts continually monitor the health and wellness space and we update our articles when new information becomes available.
Wed 24 Dec 2025
Edited by Dr Gillian Hill BVSc (Hons)Dr Carla Paszkowski BVSc (Hons)
Veterinarian
Dr. Carla graduated from the University of Queensland in 2013 with a Bachelor of Veterinary Science and worked for a number of years in small animal clinics across South East Queensland. While Carla enjoys most facets of clinical veterinary work, she holds a special passion for feline medicine, pocket pets, and nutrition.
