Roundworms in Cats and Kittens: Signs, Treatment and Human Risk

By Dr Duncan Houston

Finding a long, cream-coloured worm in your cat’s vomit or stool is deeply unpleasant, but it is also useful information. Roundworms are common, treatable intestinal parasites, particularly in kittens and cats that hunt.

Many infected cats show no obvious illness. Heavier infections can cause vomiting, diarrhoea, a pot-bellied appearance and poor growth. Young kittens may also develop respiratory signs while roundworm larvae migrate through the lungs.

The real concern is not only the worms currently inside the cat. Roundworm eggs can contaminate the environment, remain infectious for years and occasionally cause serious disease in people.

Quick Answer

Roundworms are large intestinal worms most commonly caused by Toxocara cati in cats. Cats become infected by swallowing eggs from a contaminated environment, eating infected prey or, in the case of young kittens, consuming larvae through their mother’s milk.

Treatment is usually straightforward, but one dose may not be enough. Kittens require repeated deworming, adult cats need ongoing parasite control based on their lifestyle, and litter trays should be cleaned promptly to prevent long-lived eggs from contaminating the environment. (Companion Animal Parasite Council)

Roundworms in Cats at a Glance

Question	Practical answer
What causes feline roundworms?	Most infections are caused by Toxocara cati. Toxascaris leonina is less common
Which cats are most at risk?	Kittens, hunting cats, outdoor cats, shelter cats and cats without routine parasite prevention
What do the worms look like?	Cream or light-tan worms resembling spaghetti, commonly several centimetres long
Can kittens get them from their mother?	Yes, T. cati larvae may pass through milk. Infection before birth has not been demonstrated
Are fresh faeces immediately infectious?	Usually no. Toxocara eggs generally require two to four weeks in the environment to become infectious
Do all infected cats look sick?	No. Many adult cats have no visible signs
How are roundworms diagnosed?	Centrifugal faecal flotation, sometimes combined with faecal antigen testing or PCR
How are they treated?	With a veterinarian-selected anthelmintic, often followed by repeated treatment or monthly prevention
Can people become infected?	Yes. Accidental ingestion of embryonated Toxocara eggs can cause toxocariasis
When is it urgent?	Repeated vomiting, breathing difficulty, collapse, severe weakness or a painful, distended abdomen

These recommendations reflect current Companion Animal Parasite Council guidance. (Companion Animal Parasite Council)

What Are Roundworms?

Roundworms are stout, cylindrical nematodes that live as adults in the small intestine.

The two main roundworms affecting domestic cats are:

• Toxocara cati

• Toxascaris leonina

Toxocara cati is the more common and clinically important species. It can infect cats throughout life, migrate through the liver and lungs during development, pass to kittens through milk and contaminate the environment with eggs capable of infecting people. (Companion Animal Parasite Council)

Toxascaris leonina is less commonly associated with significant illness in cats. Its larvae remain within the intestinal system rather than migrating through the liver and lungs. Infection still requires treatment because affected cats can continue shedding eggs into their environment. (Companion Animal Parasite Council)

What Do Cat Roundworms Look Like?

Adult Toxocara cati worms are pale cream, yellowish or light tan and are easily visible without a microscope. Males may reach approximately 6 cm, while females may approach 10 cm. Their broad front end can have an arrowhead or cobra-like appearance when examined closely. (wcvm)

Owners commonly describe them as:

• Spaghetti-like

• Smooth and cylindrical

• Several centimetres long

• Unsegmented

• Occasionally curled into a loose coil

Roundworms should not be confused with tapeworm segments. Tapeworm segments usually resemble small grains of rice around the anus, bedding or stool. Roundworms resemble entire pieces of pale spaghetti.

How Do Cats Get Roundworms?

Cats acquire roundworms through several routes.

Swallowing Infectious Eggs

An infected cat passes microscopic, non-infectious eggs in its stool.

Under suitable environmental conditions, Toxocara eggs develop into the infectious larval stage over approximately two to four weeks. A cat becomes infected after swallowing these eggs from contaminated soil, paws, fur, litter, food or other surfaces. (Companion Animal Parasite Council)

Toxascaris leonina eggs may become infectious more quickly, sometimes within approximately one week. (Companion Animal Parasite Council)

Eating Rodents, Birds or Other Prey

Roundworm larvae may remain dormant within the tissues of rodents, birds and other animals known as paratenic or transport hosts.

When a cat hunts and eats one of these animals, the larvae develop into adult worms within the cat’s intestine. This is an important source of infection and reinfection in outdoor and hunting cats. (Companion Animal Parasite Council)

Earthworms and other invertebrates may also carry larvae and contribute indirectly to transmission through the food chain. (Companion Animal Parasite Council)

Drinking Milk From an Infected Queen

Young kittens can acquire Toxocara cati larvae through their mother’s milk.

Milk transmission is particularly associated with queens that acquire infection during late pregnancy or lactation. The larvae can reach the mammary glands and remain in the milk during nursing. (wcvm)

Unlike canine Toxocara canis, prenatal transmission of Toxocara cati through the placenta has not been demonstrated. Kittens are infected after birth rather than while still in the uterus. (Companion Animal Parasite Council)

Can Indoor Cats Get Roundworms?

Yes.

Indoor cats have a lower hunting and environmental exposure risk, but infection remains possible through:

• Infection acquired before adoption

• Larvae acquired through the mother’s milk

• Rodents entering the home

• Contaminated soil on footwear

• Other animals in the household

• Inadequate previous deworming

• Access to balconies, gardens or enclosed outdoor spaces

CAPC notes that Toxocara cati infection occurs in cats of all lifestyles, although outdoor access and hunting increase the risk. (Companion Animal Parasite Council)

What Happens After a Cat Swallows Roundworm Eggs?

After a cat swallows an infectious Toxocara egg, the larva hatches in the intestine.

The larva then travels through the liver and into the lungs. From the lungs, it moves into the airways, is coughed upwards, swallowed and returned to the digestive tract, where it matures into an adult worm within the small intestine. (Companion Animal Parasite Council)

This is called hepatotracheal migration.

Larvae acquired by eating an infected rodent or bird follow a simpler pathway and develop in the intestinal tract without completing the same liver and lung migration. (Companion Animal Parasite Council)

The prepatent period, meaning the time between infection and the production of eggs detectable in faeces, is approximately eight weeks for Toxocara cati. It is approximately eight to ten weeks for Toxascaris leonina. (Companion Animal Parasite Council)

This matters because a recently infected cat can have immature worms before an ordinary faecal flotation becomes positive.

What Are the Signs of Roundworms in Cats?

Many infected adult cats show no obvious symptoms.

Clinical disease is most common in kittens and cats carrying a heavy worm burden. (Companion Animal Parasite Council)

Common Signs in Kittens

Affected kittens may develop:

• A rounded or pot-bellied abdomen

• Poor weight gain

• Failure to thrive

• A thin body despite a large abdomen

• Dull or poor coat quality

• Diarrhoea

• Mucus in the stool

• Vomiting

• Reduced appetite

• Abdominal discomfort

• Visible worms in vomit or stool

Migrating larvae may also cause coughing, noisy breathing or other respiratory signs, particularly in young kittens with a substantial infection. (Companion Animal Parasite Council)

Common Signs in Adult Cats

Adult cats may remain clinically normal.

When signs occur, they may include:

• Vomiting

• Occasional diarrhoea

• Weight loss or poor condition

• Abdominal discomfort

• Visible worms in vomit

• Reduced coat quality

Adult worms sometimes move from the small intestine into the stomach, irritating the gastric lining and causing the cat to vomit the worm. (Companion Animal Parasite Council)

Can Roundworms Cause Intestinal Obstruction?

A very heavy worm burden can potentially contribute to serious intestinal dysfunction, particularly in a small kitten. True mechanical obstruction appears uncommon in cats, but repeated vomiting, severe abdominal enlargement, pain and failure to pass stool should never be managed at home as “just worms”.

Those signs require urgent investigation for obstruction, intussusception, a foreign body or another gastrointestinal emergency.

How Worried Should You Be?

Lower Risk

The cat:

• Has one visible worm in the stool

• Remains bright and active

• Eats and drinks normally

• Has no vomiting or diarrhoea

• Breathes normally

• Is not a very young or fragile kitten

What it likely means: An intestinal roundworm infection is present, but the cat is currently stable.

What to do: Photograph or collect the worm safely, arrange a veterinary appointment and begin an appropriate deworming programme within the next few days.

Moderate Concern

The cat has:

• Intermittent vomiting or diarrhoea

• A pot-bellied appearance

• Poor coat quality

• Mild weight loss

• Reduced growth

• Several worms in the stool

• A history of hunting or inadequate parasite prevention

What it may mean: A moderate worm burden is affecting gastrointestinal health or nutrition.

What to do: Arrange a veterinary examination promptly. Faecal testing, body-weight assessment and repeated deworming are likely to be needed.

High Concern

The cat has:

• Repeated vomiting

• Significant diarrhoea

• Marked weight loss

• Poor appetite

• Dehydration

• Coughing or rapid breathing

• Failure to grow

• Severe abdominal distension

• Lethargy

What it may mean: A heavy parasitic burden, lung migration or another concurrent disease may be present.

What to do: Seek same-day veterinary assessment, particularly for a kitten.

Critical

The cat has:

• Open-mouth or laboured breathing

• Collapse

• Severe weakness

• Very pale gums

• A painful, tense or rapidly enlarging abdomen

• Repeated vomiting with no stool production

• Inability to keep water down

• Minimal responsiveness

• A very young kitten that has stopped eating

What it may mean: Severe respiratory compromise, obstruction, profound dehydration or another life-threatening problem may be present.

What to do: Attend an emergency veterinary hospital immediately.

When Is This an Emergency?

Seeing a worm is unpleasant, but it is not automatically an emergency when the cat remains bright, comfortable and able to eat.

Seek immediate veterinary care when your cat develops:

• Open-mouth breathing

• Pronounced abdominal breathing effort

• Blue, grey or very pale gums

• Repeated vomiting

• Severe abdominal pain

• A firm, distended abdomen

• Inability to pass stool

• Collapse

• Severe dehydration

• Profound lethargy

• Rapid weight loss

• Complete food refusal

• Significant respiratory signs in a kitten

Do not force oral medication into a kitten that is struggling to breathe, vomiting repeatedly or unable to swallow safely.

What Else Can Look Like Roundworms?

Roundworm infection can coexist with other conditions, particularly in kittens and shelter cats.

Possible condition	Useful distinguishing features
Hookworms	Anaemia, pale gums, weakness and dark or bloody stool
Giardia	Soft or watery diarrhoea, sometimes with mucus and weight loss
Coccidiosis	Diarrhoea in kittens, occasionally with blood, dehydration or poor growth
Tritrichomonas	Chronic foul-smelling large-bowel diarrhoea with mucus, blood and straining
Tapeworms	Rice-like segments around the anus, stool or bedding
Food-responsive disease	Gastrointestinal signs associated with diet and improving during a controlled trial
Foreign body	Sudden vomiting, pain, food refusal and possible intestinal obstruction
Hairballs	Intermittent retching or vomiting, but no worm eggs on faecal examination
Pregnancy	Enlarged abdomen in an entire female, confirmed through examination or imaging
Abdominal fluid or organ enlargement	Progressive distension, breathing changes or systemic illness
Respiratory infection or asthma	Coughing and breathing changes without evidence of larval migration

A pot-bellied kitten may have worms, but pot belly alone is not enough to make the diagnosis.

What To Do Right Now

1. Photograph or Collect the Worm

Use gloves or a disposable bag.

Place the worm in a clean sealed container or take clear photographs beside a ruler or coin for scale. Your veterinarian may be able to distinguish roundworms from tapeworms or other material by appearance.

Wash your hands thoroughly afterwards.

2. Collect a Fresh Faecal Sample

Place a fresh sample in a clean, sealed container.

Avoid filling it with litter. Refrigerate it if the clinic has instructed you to do so, but do not freeze it unless the laboratory specifically requests freezing.

3. Clean the Litter Tray Promptly

Remove faeces at least daily, and preferably immediately when a known infection is present.

Freshly passed Toxocara eggs are not yet infectious. Removing stool before the eggs have time to develop is one of the most effective ways to prevent environmental contamination. (CDC)

4. Arrange Veterinary Treatment

The veterinarian needs to know:

• Your cat’s age

• Accurate body weight

• Pregnancy or nursing status

• Previous deworming dates

• Current parasite prevention

• Indoor or outdoor lifestyle

• Hunting behaviour

• Other animals in the household

• Current clinical signs

These details determine which product and schedule are safe and appropriate.

5. Do Not Use a Dog Product

Dog parasite products may contain unsafe ingredients or inappropriate concentrations for cats.

Never estimate a feline dose from a canine package. This is particularly important with combination flea, tick and worm products.

6. Do Not Give Human Deworming Medication

Human products may be ineffective, incorrectly dosed or unsafe for cats.

The treatment must cover the correct parasite and be suitable for the cat’s age and weight.

7. Do Not Pull on a Worm Protruding From the Anus

Allow the worm to pass naturally or seek veterinary assistance.

Pulling can cause discomfort or damage, especially when the visible material is not actually a roundworm.

How Are Roundworms Diagnosed?

Centrifugal Faecal Flotation

The standard test is faecal flotation with centrifugation.

Roundworm eggs are separated from the faecal material and identified under a microscope. Toxocara cati eggs have a thick, rough outer shell, while Toxascaris leonina eggs have a smoother shell. (Companion Animal Parasite Council)

CAPC recommends centrifugal flotation rather than passive flotation because centrifugation improves parasite detection. (Companion Animal Parasite Council)

Why Can the Test Be Negative?

A negative faecal flotation does not exclude every infection.

Eggs may be absent when:

• The worms are not yet mature

• Only male worms are present

• The worm burden is very low

• Egg shedding is inconsistent

• The sample is too small

• The test technique is insensitive

Faecal antigen testing and PCR can identify some infections before eggs are visible or when only non-egg-producing worms are present. CAPC recommends combining these methods with microscopic examination when broader detection is needed. (Companion Animal Parasite Council)

Identifying an Adult Worm

Adult worms may be passed in vomit or stool.

The veterinarian or laboratory may identify the species from:

• Length and shape

• The front end of the worm

• The presence of cervical alae

• Microscopic examination of eggs within a female worm

• Molecular testing where necessary

How Often Should Cats Have Faecal Tests?

CAPC recommends:

• At least four intestinal parasite examinations during the first year of life

• At least two examinations yearly for adult cats, adjusted for health, lifestyle and exposure risk

Cats that hunt, go outdoors, live in shelters or catteries, eat raw meat or have recurring parasite infections may need more frequent testing. (Companion Animal Parasite Council)

How Are Roundworms Treated?

Several veterinary anthelmintics are effective against feline roundworms.

Depending on the cat’s age, weight, location and parasite-control plan, the veterinarian may select an active ingredient such as:

• Pyrantel pamoate

• Milbemycin oxime

• Moxidectin

• Selamectin

• Emodepside

• Eprinomectin-containing combinations

• Other locally approved feline anthelmintics

Product approval, minimum age, weight requirements and activity against immature worm stages vary between countries and formulations. (Companion Animal Parasite Council)

Piperazine is licensed in some regions but may be less effective than several newer options and is not usually the preferred modern first choice when more effective feline products are available. (Companion Animal Parasite Council)

Why Is Repeat Treatment Needed?

One treatment may kill adult worms currently inside the intestine without eliminating every immature larva or preventing immediate reinfection.

Repeat treatment or transition onto an effective monthly product helps control worms that mature after the first dose. Some products also have activity against later larval stages, but this varies by formulation. (Companion Animal Parasite Council)

The mistake I see most often is giving one dose, seeing worms disappear and assuming the problem is finished.

Can Worms Appear After Deworming?

Yes.

Dead, paralysed or dying worms may pass in the stool after treatment. Occasionally, a cat may vomit a worm.

This does not automatically mean the medication failed. It may be evidence that worms are being expelled. Contact the veterinarian if the cat develops repeated vomiting, abdominal pain, marked lethargy or worsening distension.

Should Every Cat in the Household Be Treated?

The other cats should at least have their parasite history and risk assessed.

When one kitten is infected, littermates and the nursing queen are commonly exposed. CAPC recommends treating nursing queens at the same time as their litters using a product confirmed as safe for the queen’s reproductive status. (Companion Animal Parasite Council)

Dogs in the household may require their own faecal testing and species-appropriate parasite programme, particularly when Toxascaris leonina or shared environmental contamination is possible.

What Is the Recommended Kitten Deworming Schedule?

A practical CAPC-based schedule is:

Kitten age	General recommendation
2 weeks	First veterinarian-approved deworming treatment
4 weeks	Repeat treatment
6 weeks	Repeat treatment
8 weeks	Repeat treatment or begin an appropriate monthly broad-spectrum product
2 to 6 months	Continue effective monthly intestinal parasite control
After 6 months	Continue year-round monthly broad-spectrum control or use a veterinarian-directed risk-based programme

CAPC recommends beginning at two weeks and repeating treatment every two weeks until regular broad-spectrum parasite control begins. When continuous monthly prevention cannot be maintained, CAPC advises treatment every two weeks until two months of age, monthly until six months and at least quarterly thereafter. (Companion Animal Parasite Council)

Starting at two weeks also provides broader protection where feline hookworms are a concern, even though Toxocara cati usually does not begin producing detectable eggs until later. (Companion Animal Parasite Council)

Regional recommendations differ. The final schedule should follow:

• The product label

• The kitten’s weight

• Local parasite prevalence

• Outdoor and hunting exposure

• Shelter or cattery history

• Other parasites common in the region

What About Adult Cats?

Adult cats remain susceptible to Toxocara cati throughout life.

CAPC recommends year-round broad-spectrum parasite control with activity against roundworms. When monthly control cannot be maintained, adult cats should generally receive broad-spectrum treatment at least four times yearly alongside appropriate faecal testing. (Companion Animal Parasite Council)

In regions where parasite risk is lower, veterinarians may use a more individualised programme based on:

• Indoor-only versus outdoor access

• Hunting

• Raw-meat feeding

• Contact with kittens or shelter cats

• Local heartworm risk

• Previous faecal results

• Presence of young children in the household

• Pregnancy or immune compromise within the household

A genuinely indoor adult cat eating a cooked commercial diet may need a different programme from a farm cat consuming rodents every week. The risk assessment should be deliberate rather than assuming either cat is completely protected.

Can You Eliminate Roundworm Eggs From the Home?

Preventing contamination is far easier than removing established eggs.

Toxocara eggs have a thick protective shell. Once they have matured in soil or porous materials, they may remain infectious for months or years and resist many commonly used disinfectants. (Companion Animal Parasite Council)

Litter-Tray Cleaning

Use the following approach:

1. Scoop faeces promptly.

2. Empty litter completely during treatment as advised.

3. Wash the tray thoroughly with detergent and hot water.

4. Remove all visible organic material.

5. Dry the tray completely.

6. Consider steam treatment for cleanable hard surfaces where practical.

7. Replace heavily scratched or difficult-to-clean trays.

Do not rely on spraying disinfectant over dirty litter or dried faeces.

Carpet, Bedding and Hard Surfaces

Wash contaminated bedding using the hottest safe cycle and dry it thoroughly.

Vacuum and physically clean flooring. Steam may help on heat-tolerant surfaces, but no household method guarantees removal of every established egg from porous material.

Soil and Sand

Once eggs are widely distributed through soil, ordinary household disinfectants are unlikely to solve the problem.

Management focuses on:

• Removing faeces before eggs become infectious

• Restricting access to contaminated areas

• Replacing contaminated sandbox material

• Covering sandboxes when not in use

• Preventing cats from toileting in children’s play areas

• Removing heavily contaminated topsoil in exceptional situations

CAPC notes that established eggs can be extremely difficult to destroy and may require heat, steam or removal of contaminated substrate. (Companion Animal Parasite Council)

Can People Catch Roundworms From Cats?

Yes.

People can develop toxocariasis after accidentally swallowing infectious Toxocara eggs from contaminated soil, hands, food or other environmental material. The parasite does not normally develop into an adult intestinal worm in people. Instead, larvae migrate through human tissues. (CDC)

Human disease may include:

• Visceral larva migrans

• Ocular larva migrans

• Neural larva migrans

• Less specific or covert toxocariasis

Many human infections produce no symptoms or only mild illness. Rare severe cases can affect the liver, lungs, nervous system or an eye and may cause permanent visual injury. (Companion Animal Parasite Council)

Who Is Most at Risk?

Young children are at greater risk, particularly when they:

• Play in contaminated soil or sand

• Put dirty hands or objects into their mouths

• Eat soil

• Have access to uncovered sandboxes

• Live around untreated free-roaming cats or dogs

People are not usually infected simply by standing near a cat. The typical route is accidental ingestion of infectious eggs that have matured in the environment. (CDC)

Is Fresh Cat Faeces Immediately Dangerous?

Freshly passed Toxocara eggs are not immediately infectious.

They usually require two to four weeks in the environment before the larva develops enough to infect a cat or person. This is why daily litter cleaning is such an effective public-health measure. (CDC)

Fresh stool should still be handled hygienically because other parasites and bacteria may be immediately infectious.

How Can Human Risk Be Reduced?

• Maintain appropriate parasite control for every cat.

• Scoop litter trays daily.

• Wear gloves when cleaning heavily contaminated areas.

• Wash hands after handling litter or soil.

• Keep children away from animal faeces.

• Cover sandboxes.

• Prevent cats from defecating in vegetable gardens.

• Wash home-grown produce.

• Prevent hunting where possible.

• Do not feed raw or undercooked prey meat.

CDC specifically recommends veterinary testing and treatment, handwashing and prompt disposal of pet waste. (CDC)

Anyone concerned about possible human exposure or symptoms should speak with a medical doctor. The cat’s veterinarian cannot diagnose or treat human toxocariasis.

What Is the Prognosis?

The prognosis is excellent for most cats once an appropriate treatment and prevention programme is followed.

Kittens may need time to:

• Regain weight

• Improve coat condition

• Lose the pot-bellied appearance

• Recover from diarrhoea

• Rebuild strength

• Clear successive waves of maturing worms

Persistent signs after appropriate treatment may indicate:

• Reinfection

• Incomplete treatment

• Incorrect dosing

• Another parasite

• A gastrointestinal disorder

• An obstruction or foreign body

• Poor nutrition

• An unrelated respiratory condition

A follow-up faecal examination helps confirm that egg shedding has stopped and identifies concurrent parasites.

Common Roundworm Mistakes

Giving Only One Treatment

Repeat treatment or monthly prevention is often required because immature stages may continue developing after the first dose.

Skipping Deworming Because the Cat Looks Healthy

Many infected adult cats show no symptoms while continuing to contaminate the environment with eggs.

Assuming Indoor Cats Have No Risk

Kittens may arrive already infected, and indoor cats can encounter rodents, contaminated material or untreated household animals.

Using the Same Product for Dogs and Cats

Product ingredients, concentrations and minimum ages differ. Some canine parasite products are dangerous to cats.

Relying Only on Visible Worms

Cats may shed thousands of microscopic eggs without passing an adult worm that the owner can see.

Treating the Kitten but Not the Queen or Littermates

Shared exposure allows infection to continue circulating.

Believing Bleach Will Sterilise Contaminated Soil

Established Toxocara eggs resist many ordinary disinfectants. Prompt faeces removal is far more effective than trying to disinfect an already contaminated garden.

Confusing Roundworms With Tapeworms

Roundworms resemble spaghetti. Tapeworm segments resemble grains of rice.

How Can Roundworms Be Prevented?

Begin Kitten Deworming Early

Start at the age recommended by your veterinarian, commonly two weeks under CAPC-style programmes, and complete every scheduled follow-up treatment. (Companion Animal Parasite Council)

Use Ongoing Broad-Spectrum Prevention

Select a feline product that covers the parasites relevant to your cat’s age, lifestyle and region.

Test Faeces Regularly

Faecal testing remains important even when preventive medication is used because:

• Doses may be missed

• Products differ in parasite coverage

• Reinfection occurs

• Other intestinal parasites may be present

Prevent Hunting and Scavenging

Keeping cats indoors or within a secure enclosure reduces exposure to infected rodents, birds and contaminated soil. (Companion Animal Parasite Council)

Avoid Raw Prey and Raw Meat Diets

Commercially prepared or properly cooked diets reduce exposure to larvae within animal tissues. (Companion Animal Parasite Council)

Maintain Good Litter Hygiene

Remove stool daily, clean trays regularly and provide enough trays to prevent excessive contamination in multi-cat homes.

Protect Human Play Areas

Cover sandboxes and prevent cats from toileting in gardens, playgrounds or children’s sand areas. (Companion Animal Parasite Council)

Frequently Asked Questions

Can roundworms pass directly from one cat to another?

Not usually through immediate casual contact. Cats generally become infected after swallowing matured eggs from the environment, eating an infected transport host or, as kittens, drinking infected milk.

Freshly passed Toxocara eggs need time in the environment before they become infectious. (Companion Animal Parasite Council)

How many deworming treatments does a kitten need?

Kittens commonly begin treatment at two weeks, repeat every two weeks until approximately eight weeks, then receive effective monthly control until at least six months of age. The precise schedule depends on the product and regional veterinary guidance. (Companion Animal Parasite Council)

Can I catch roundworms by touching my cat?

The main human risk comes from accidentally swallowing infectious eggs from contaminated soil, hands or surfaces rather than from ordinary contact with a clean, regularly treated cat.

Handwashing and routine parasite control keep the risk low. (CDC)

Why did my cat vomit a worm?

Adult Toxocara cati may move from the small intestine into the stomach, irritate the stomach lining and be expelled in vomit.

The cat should still receive veterinary treatment and follow-up because additional worms or immature stages may remain. (Companion Animal Parasite Council)

Can roundworms go away without treatment?

An individual adult worm may eventually die, but untreated cats can remain infected, become reinfected and continue contaminating the environment.

Veterinary treatment is recommended even when the cat has no symptoms.

Final Thoughts

Roundworms are common, but they should not be ignored.

The most important points are:

1. Toxocara cati is the main roundworm affecting cats.

2. Kittens can acquire larvae through their mother’s milk.

3. Prenatal transmission has not been demonstrated in cats.

4. Cats also become infected by swallowing eggs or eating infected prey.

5. Many adult cats show no obvious symptoms.

6. Kittens may develop poor growth, pot belly, diarrhoea, vomiting and respiratory signs.

7. Freshly passed Toxocara eggs are not immediately infectious.

8. Eggs generally require two to four weeks to develop in the environment.

9. Once mature, eggs may remain infectious for years.

10. Centrifugal faecal flotation is the standard diagnostic test.

11. Antigen and PCR testing can detect some infections missed by flotation.

12. One treatment may not complete the entire control programme.

13. Kittens require repeated deworming followed by ongoing prevention.

14. Nursing queens and littermates should not be forgotten.

15. Daily litter cleaning prevents eggs from becoming infectious.

16. Hunting and eating prey create an important reinfection risk.

17. Toxocara cati can infect people and occasionally cause serious disease.

18. Breathing difficulty, collapse, repeated vomiting or a painful, distended abdomen requires urgent veterinary care.

The mistake that causes the greatest harm is treating only the worm that was visible. The adult worm is one part of the problem. The immature stages, other exposed cats and long-lived eggs in the environment all need to be considered.

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ASK A VET™ can help you organise photographs, faecal-test results, kitten deworming dates and household parasite-control plans while you work directly with your veterinarian. A kitten with breathing difficulty, repeated vomiting, severe weakness, collapse or a painful swollen abdomen still requires immediate hands-on veterinary care.