Can Kids Get Worms From Cats? Symptoms & Prevention

Children can catch certain worms from cats, and the risk is higher than many pet owners realize. The main culprits are roundworms (Toxocara cati) and hookworms (Ancylostoma species), both of which live in a cat’s intestines and shed eggs or larvae through feces. Kids don’t usually pick up the worms directly from stroking or cuddling a cat; the typical route is contact with contaminated soil, sandboxes, or surfaces where microscopic eggs have had time to become infectious. Because young children are prone to putting dirty hands in their mouths and playing in soil, they face a disproportionate share of the exposure.

How Roundworms Pass From Cats to Children

Adult Toxocara roundworms live in the small intestine of cats and dogs, where they release eggs that pass out in feces. Those eggs don’t become infectious immediately. They need a few weeks in warm, moist soil to develop the larval stage that can actually cause disease in a person. Once mature, however, the eggs are remarkably tough and sticky, surviving in soil for months or even years.

Children become “accidental hosts.” A toddler crawling on a floor where a cat has tracked in contaminated material, or a school-age child digging in a park sandbox, can pick up the microscopic eggs on fingers that then go straight to the mouth.¹ Because kids are unlikely to wash their hands consistently after every outdoor play session, the window for accidental ingestion is wide open. The eggs are far too small to see with the naked eye, so contaminated soil looks and feels perfectly normal.

Once swallowed, the larvae hatch in the child’s gut. Unlike in a cat, where the worms settle down and complete their life cycle, in a human the larvae can’t mature into adult roundworms. Instead, they wander through various organs and tissues, which is precisely what causes problems.

What Hookworm Transmission Looks Like

Hookworms take a different path into the body. Cat and dog hookworm larvae hatch in warm, damp soil and actively penetrate human skin on contact. A child walking barefoot on a contaminated beach, or sitting in moist sand or dirt where an infected cat has defecated, can pick up the larvae through the soles of the feet, the buttocks, or the hands.²

The larvae bore into the outer layer of skin and start migrating, but they lack the enzymes needed to punch through deeper tissues. They get stuck in the epidermis, tunneling forward a few millimeters to centimeters each day and leaving behind a raised, winding, intensely itchy track. This condition is called cutaneous larva migrans, and it’s one of the most visually distinctive parasitic skin infections you’ll encounter. The itching is caused by the inflammatory reaction to enzymes the larvae secrete as they push through the skin.²

The incubation period is usually about ten to fifteen days after the larvae enter the skin. The track typically starts as a single red line that gradually snakes outward and can grow to more than ten centimeters long. It looks alarming, but hookworm larvae from cats almost never penetrate deep enough to reach internal organs in humans. Treatment with antiparasitic medication clears the infection relatively quickly.

Symptoms of Roundworm Infection in Children

When Toxocara larvae migrate through a child’s body, the symptoms depend on where the larvae end up. Doctors recognize two main patterns, and occasionally both overlap in the same child.

Visceral larva migrans (VLM) occurs when larvae travel through the liver, lungs, or other internal organs. Children with VLM may develop a persistent cough, wheezing, fever, fatigue, and abdominal pain. Blood tests typically show elevated levels of a type of white blood cell called an eosinophil, which the immune system sends to fight parasitic invaders. Many mild cases produce vague symptoms that parents attribute to a lingering cold or stomach bug, so the infection can go unrecognized for a long time.

Ocular larva migrans (OLM) happens when a larva reaches the eye. Even a single larva lodging in the retina can cause blurred vision, eye pain, or in severe cases permanent vision loss in the affected eye. A case series involving schoolboys documented children with both visceral and ocular involvement simultaneously, including one teenager who developed severe inflammation in the eye leading to unilateral blindness alongside chronic abdominal pain.³ Ocular cases are uncommon, but they’re the reason toxocariasis is taken seriously by pediatricians and ophthalmologists.

Diagnosis is tricky because the larvae don’t show up in a child’s stool (they never mature into egg-laying adults in humans). Doctors rely on blood antibody tests, imaging, and clinical suspicion. A review in Clinical Microbiology Reviews described both VLM and OLM as “serious health problems” and noted that diagnosis and treatment remain difficult.⁴

Why Children Are at Higher Risk Than Adults

Several behaviors make young children the demographic most likely to pick up cat- or dog-derived worms. Toddlers and preschoolers explore the world with their mouths. They eat dirt on purpose sometimes (a behavior called geophagia), and they play on floors and in sandboxes where fecal contamination may be invisible. A case-control study of Toxocara infection in children found that geophagia roughly tripled the risk, while having a litter of puppies in the home raised it about fivefold.⁵ Although that study focused on dogs, the mechanism is the same with cats: more fecal material in the child’s environment means more opportunity for egg ingestion.

A cross-sectional study of Dutch elementary schoolchildren found that about 8 percent tested positive for Toxocara antibodies, indicating past or current exposure, with boys affected more often than girls.⁶ That figure is from a high-income European country with generally good sanitation. In tropical regions and areas with large populations of stray cats and dogs, seroprevalence in children can be much higher.

Immunocompromised children face additional concerns. A pilot project in Chile that integrated veterinary and pediatric care found that pets in these families harbored various zoonotic agents, reinforcing the value of coordinated screening and education when a child’s immune defenses are weakened.⁷

The Role of Stray and Outdoor Cats

Household cats that live strictly indoors and eat commercial food present a much lower risk than cats that roam outdoors, hunt, or live as strays. Outdoor cats are far more likely to pick up roundworms and hookworms from prey or contaminated soil, and they deposit feces in gardens, parks, and playgrounds rather than in a litter box that an adult cleans.

Stray cats in urban areas pose a particular problem. A study of gastrointestinal parasites in stray cats in southwestern Iran highlighted that the growing number of feral cats in residential areas, combined with their habit of defecating in public environments, contributes to soil contamination with helminth eggs, larvae, and protozoan cysts. The researchers emphasized that children who play in these areas face the highest risk of picking up infections like toxocariasis and larva migrans.⁸

Playground sandpits are an underappreciated hotspot. Research in Lisbon’s public parks found that Toxocara cati was the dominant species contaminating playground sandpits, even in fenced playgrounds that dogs couldn’t easily access. Stray cats, being agile climbers, bypassed the fences entirely. The study’s molecular analysis confirmed cats, not dogs, were the primary source of contamination in those sandpits.⁹ Similar concerns apply to community gardens and food-growing areas. A California study found that free-roaming cat colonies were an important source of Toxoplasma gondii contamination in urban public spaces where people grow food and recreate.¹⁰

How Often Cats Actually Get Dewormed (and Why It Matters)

Veterinary parasitologists have guidelines recommending that cats in high-risk categories receive monthly deworming treatment. High-risk cats include those that hunt, catch prey, or live in households with young children or elderly people. A large European survey found that between a third and two-thirds of cats fell into a risk category where monthly deworming was recommended. Despite that, cats in the survey were dewormed on average only about twice a year. That frequency is well below the four-times-a-year minimum shown to be necessary to meaningfully reduce the shedding of Toxocara eggs into the environment.¹¹

The gap matters because even a well-loved pet cat that looks perfectly healthy can be shedding worm eggs. Cats with low-level roundworm infections often show no obvious symptoms. They eat normally, maintain a healthy weight, and give no outward sign that their stool is a source of infective eggs. By the time a parent notices anything wrong with the cat, thousands of eggs may already be in the litter box or the backyard. This is why routine, preventive deworming on a schedule, rather than reactive treatment after symptoms appear, is the approach that actually reduces risk for children in the home.

Practical Prevention Steps

The good news is that preventing transmission is straightforward, even if it requires consistency. The measures fall into two categories: keeping the cat’s parasite burden low and minimizing your child’s contact with contaminated material.

• Regular deworming: Talk to your vet about a deworming schedule based on your cat’s lifestyle. Indoor-only cats with no hunting access need less frequent treatment than outdoor cats. At minimum, most guidelines suggest at least four treatments per year for cats that go outside or have contact with young children.
• Prompt litter box cleaning: Roundworm eggs need several weeks in the environment before they become infectious. Scooping the litter box daily breaks that cycle by removing feces before the eggs have time to mature. Wear gloves while cleaning and wash your hands afterward.
• Handwashing after outdoor play: Teach children to wash their hands with soap and water after playing outside, especially after digging in soil or sand. This single habit probably prevents more infections than any other intervention.
• Cover sandboxes: If you have a backyard sandbox, cover it when not in use. Cats treat uncovered sandboxes as inviting litter boxes, and fenced enclosures don’t stop them since they climb easily.
• Shoes outdoors: Hookworm larvae penetrate bare skin. Having children wear shoes when playing outside, particularly in warm, damp environments, sharply reduces hookworm risk.
• Flea control: Fleas can serve as intermediate hosts for certain tapeworms. Keeping your cat on a regular flea prevention program helps close off another transmission pathway.¹²

None of these steps require you to keep children away from cats. The affection, companionship, and developmental benefits of growing up with pets are real. The goal is to manage the parasites, not to eliminate the relationship.

Toxoplasma and the “Worms” Confusion

Many parents who search for information about worms from cats end up reading about Toxoplasma gondii, which is a single-celled parasite rather than a worm. The confusion is understandable because the transmission route overlaps: cats shed Toxoplasma oocysts in their feces, and the oocysts become infectious in soil after a few days.¹³ Children can ingest them through the same dirty-hands-to-mouth route that spreads roundworm eggs.

In healthy children, Toxoplasma infection usually produces no symptoms or mild flu-like illness that resolves on its own. The major concern is for pregnant women (risk of congenital infection) and for immunocompromised individuals. Toxoplasma is worth knowing about in the context of cat-to-human transmission, but it is biologically distinct from the helminth worms (roundworms, hookworms, tapeworms) and won’t show up on a stool test looking for worm eggs. If your pediatrician suspects Toxoplasma, they’ll order a blood antibody test rather than a stool sample.

When to See a Doctor

Many mild roundworm exposures in children produce either no symptoms at all or vague complaints like intermittent belly pain and low-grade eosinophilia that a routine blood test might catch incidentally. These cases often resolve without treatment as the larvae die off. However, some signs warrant prompt medical attention:

• Persistent cough or wheeze: Especially if it doesn’t respond to asthma medication and the child has a history of soil contact or a cat in the home.
• Vision changes: Any new blurriness, floaters, or pain in one eye in a child with potential Toxocara exposure should be evaluated urgently. Ocular larva migrans can cause irreversible damage if untreated.
• Itchy, snaking skin tracks: The classic sign of hookworm larva migrans. A doctor can confirm the diagnosis on sight and prescribe antiparasitic treatment to stop the itching and kill the larvae.
• Unexplained fever and fatigue: Particularly with elevated eosinophils on a blood count, in a child with known soil or sandbox exposure.

Mention your pets to the pediatrician. Many doctors don’t think to ask about animal contact during routine visits, and knowing there’s a cat (especially an outdoor cat) in the home can shift the differential diagnosis considerably. A pilot program studying integrated veterinary-pediatric care for families with immunocompromised children confirmed that coordinating information about the pet’s health with the child’s medical team improved outcomes for both.⁷

The Sandbox Problem

Public sandboxes deserve their own mention because they sit at the intersection of two risk factors: children playing in sand with their hands, and cats using uncovered sand as a toilet. The Lisbon study referenced earlier found Toxocara cati eggs in playground sandpits that were surrounded by high fences with locked gates at night, meaning dogs weren’t the problem. Cats jumped the fences.⁹ The researchers concluded that existing hygiene and disinfection measures were insufficient to keep parasite levels low.

For home sandboxes, a tight-fitting cover is the simplest fix. For public playgrounds, the situation is harder to control individually. If your child plays in public sandpits, emphasizing thorough handwashing before eating and discouraging hand-to-mouth behavior during play are the most practical defenses. Some municipalities have experimented with replacing sand with rubber mulch or wood chips in play areas, which are less attractive to cats and less hospitable to larvae, though these materials have their own drawbacks.

Hookworm larvae also thrive in warm, damp sand, making tropical and subtropical beaches another exposure point. If your family vacations in a warm climate and your child plays barefoot on a beach frequented by stray cats or dogs, hookworm larva migrans is a real possibility. The itchy tracks typically show up on the feet or buttocks a week or two after the trip, and doctors in temperate countries sometimes fail to recognize them because they don’t see the condition often.