Can Cats Eat Worms? Worms, Waxworms and Parasite Risk

Name: Can Cats Eat Worms? Worms, Waxworms and Parasite Risk
Creator: Dr. Zubair Khalid

By Dr. Zubair Khalid, DVM, MS, PhD · 2026-10-02

Cats do eat worms, and most of the time a single worm or insect is not an emergency. The real concern is not the worm itself but the parasites and bacteria it can carry, plus the choking and digestive risks of eating anything unusual. If you are asking "can cats eat worms," the honest answer is that it depends entirely on the type of worm and where it came from.

This article is educational and is not a substitute for veterinary diagnosis or treatment.

Quick Answer

Earthworms, grubs, and garden worms are not toxic to cats, but they can carry parasite larvae and bacteria from soil and feces.
Waxworms (the larvae of wax moths) are not poisonous to cats, but they are high in fat and are sold as reptile food, not cat food.
The biggest worm-related danger is roundworm infection, which cats pick up by eating prey such as mice that carry the parasite [1][2].
Never offer a worm or insect that has been dusted, gut-loaded, or kept in a container with additives, bedding chemicals, or dyes.
If your cat ate a worm and seems fine, watch for vomiting, diarrhea, or worms in the stool, and call your vet if anything changes.

Can Cats Eat Worms? The Direct Verdict

A cat that catches and swallows a worm outside is doing something cats have done for thousands of years. Cats are predators, and their natural diet includes beetles, cockroaches, crickets, mice, and frogs, all of which can carry parasite larvae [1]. Eating a worm is not automatically harmful, but it is also not a safe, planned snack.

The verdict splits by worm type. A plain earthworm from clean soil is low risk in the moment. A worm that has been living in another animal's intestines, or in soil contaminated with feces, is a different story. That is where roundworms, tapeworms, and other intestinal parasites enter the picture.

Roundworms are the most common intestinal parasite in cats, affecting 25% to 75% of cats, with higher rates in kittens [2]. Adult roundworms are three to five inches long, cream-colored, and live in the cat's intestine, where they survive by eating food the host has ingested [2]. If your cat eats a rodent carrying roundworm larvae, that is a direct route to infection [2].

So the practical answer is this. A cat can physically eat a worm, and one worm usually will not cause immediate harm. But you should not encourage it, and you should not treat it as a free treat.

Can Cats Eat Waxworms?

Waxworms are the caterpillar larvae of wax moths. They are commonly sold in pet stores as food for reptiles, birds, and sometimes fish. Owners often ask "can cats have wax worms" because their cat batted a container off a shelf or stole one during feeding time.

Waxworms are not toxic to cats. A single waxworm is unlikely to poison your cat. The problem is what waxworms are and what they are not. They are not a balanced cat food, they are very high in fat, and they are raised in conditions meant for reptiles, not for a cat's digestive system.

There is also a handling issue. Waxworms are often kept in containers with bedding, bran, or commercial gut-loading products. Some of those products contain additives that are not intended for cats. If your cat ate a waxworm straight from a clean container, the risk is low. If your cat ate the bedding, the container gel, or a worm dusted with a reptile supplement, call your veterinarian or a pet poison hotline for guidance.

Do not make waxworms a regular treat. A cat's nutritional needs are met by a complete and balanced cat food, and diet strongly influences the gut microbiome and overall health [3]. Table scraps and novelty insects should stay a tiny fraction of the diet, if they appear at all.

Do Cats Eat Worms on Their Own?

Yes. Cats eat worms and insects on their own, often without their owners seeing it happen. Outdoor cats hunt. Indoor cats chase and swallow flies, moths, and spiders. Some cats eat grass and accidentally take in small worms or larvae with it.

A study using DNA analysis of cat scat found that consumption of wild prey and owner-reported capture do not always match [4]. In that study, only one instance of wild prey consumption was detected, a California vole, even though the owner had not seen any prey brought home in the 24 hours before sampling [4]. In three cases where owners reported their cats brought home intact prey, no prey DNA was found, likely because the cats did not actually eat any part of it [4].

That finding matters for owners. You may never see your cat eat a worm, and you may still find evidence later. The reverse is also true. A cat that brings home a mouse may not have eaten it at all.

Parasite Risk: What Worms Can Pass to Your Cat

This is the part that deserves real attention. Worms are not just protein. They are transport vehicles for parasites.

Roundworms

Cats become infected with Toxocara cati by ingesting eggs or rodents that have larvae in their tissues [2]. Kittens can also ingest larvae that pass through an infected mother's milk, sometimes becoming infected soon after birth [2]. Cats become infected with Toxascaris leonina by ingesting infective eggs in the environment or larvae in the tissues of rodents [2]. That second parasite cannot pass across the placenta or the mother's milk, so cats under two months of age rarely carry it [2].

Roundworm eggs passed in feces need several days to several weeks to develop into the infective larval stage [2]. That means fresh feces are less risky than old, weathered feces in soil. It also means a cat that eats a worm from contaminated dirt may be picking up infective eggs.

What infection looks like

Often there are no signs at all. When signs appear, they can include diarrhea, poor growth, a dull coat, or a distended, swollen abdomen [1]. Worms may be vomited or passed in feces [1]. In kittens that have eaten infective eggs, the larvae penetrate the intestinal wall, travel to the lungs through the bloodstream, get coughed up, swallowed, and mature into egg-producing adults in the small intestine [1]. Adult cats generally have some resistance to infection, but immunity can be suppressed around the time they give birth, and significant numbers of eggs may then appear in their feces [1].

Other parasites worth knowing about

Filarial parasites are less common but real. A survey of 300 owned cats in Kerala, India, found that four cats (1.33%) tested positive for circulating microfilariae, identified as Brugia malayi and Dirofilaria repens [5]. This is a regional finding, not a United States statistic, but it shows that cats can carry worm-borne parasites that are not always on an owner's radar.

Some worm-related infections can spread to people. Use caution when handling an infected pet, because the worms can cause serious disease in humans [1]. If you want to understand that risk in more detail, see Can Humans Catch Cat Worms.

Form-by-Form Safety Table

Form	Safe?	Notes
Earthworm from clean garden soil	Low risk	Not toxic, but can carry soil bacteria and parasite eggs
Earthworm from soil with dog or cat feces	Unsafe	High risk of roundworm and other parasite eggs
Waxworm from a clean container	Low risk in small amounts	High in fat, not a balanced food, watch for additives
Waxworm with bedding or gel	Unsafe	Bedding and gel are not meant to be eaten
Mealworm or superworm	Low risk in small amounts	Hard exoskeleton can cause choking or GI upset
Insect dusted with reptile supplement	Unsafe	Supplements are dosed for reptiles, not cats
Wild-caught insect	Unsafe	Unknown pesticide and parasite exposure
Dead or decaying worm	Unsafe	Bacterial growth and possible toxin exposure

How to Offer a Worm or Insect Safely

If you want to give your cat an insect treat, buy feeder insects from a reputable pet store and keep them in a clean container. Offer one at a time. Watch your cat chew and swallow. Never leave a container of live worms where your cat can knock it over and eat the contents.

Avoid these preparations and parts:

Any insect dusted with calcium, vitamin, or mineral powder made for reptiles
Any insect kept on gel, dye, or commercial bedding
Wild-caught insects from lawns treated with pesticides or fertilizer
Dead, crushed, or decaying worms
Worms from soil where dogs, cats, or wildlife defecate
Any worm or insect mixed with garlic, onion, salt, xylitol, or seasoning

Garlic, onion, xylitol, and excess salt are all harmful to cats. If a worm or insect was prepared with any of these, treat it as a possible poisoning and call your veterinarian or a pet poison hotline right away.

What to Do If Your Cat Ate Too Much or a Dangerous Form

If your cat ate one clean worm and is acting normal, you can watch at home. Offer water, keep the diet normal, and check the litter box over the next day or two.

Call your veterinarian the same day if your cat ate:

A large number of worms or insects at once
A worm or insect from contaminated soil or feces
Anything dusted, gut-loaded, or kept with additives
A wild insect from a treated lawn or garden

Go to an emergency clinic now if you see:

Repeated vomiting or vomiting that will not stop
Severe diarrhea or blood in the stool
A swollen, painful abdomen
Trouble breathing, coughing, or gagging
Drooling, tremors, weakness, or collapse
Worms in the vomit or stool along with any of the above

For deworming, drugs are available from your veterinarian to treat infection [1]. Do not guess a dose or use a product made for another species. Your veterinarian calculates the dose from your cat's weight and health, and the right product depends on which parasite is present.

If you find tapeworm segments on your cat's bedding or near the tail, read Tapeworm Medicine For Cats before you buy anything over the counter.

Safer Alternatives to Worms and Insects

You do not need to feed worms to give your cat enrichment. Better options include:

A complete and balanced commercial cat food that meets your cat's life stage needs
Commercially prepared cat treats given in small amounts
Cooked, plain, unseasoned meat in tiny pieces, if your vet approves
Food puzzles and treat balls that make your cat work for kibble
Interactive play that mimics hunting, such as wand toys and laser pointers used correctly
Safe cat grass grown indoors from clean seed

If your cat hunts outdoors, keep up with routine deworming as directed by your veterinarian. Isolation of sick animals and thorough washing of pet living areas help reduce the spread of parasites at home [1]. If you also feed or handle wild game, see Can Cats Eat Venison? Wild Game Parasite Testing for related safety information.

Limitations and When to Contact a Veterinarian

This article cannot tell you whether your specific cat is infected. Only a veterinarian can examine your cat, test the stool, and decide on treatment. Individual cases need a veterinarian.

Contact your veterinarian for a routine visit if your cat has had worms or insects in the diet and you notice:

Weight loss or a failure to gain weight in a kitten
A dull, rough coat that does not improve
A potbellied appearance, especially in a kitten
Worms visible in the stool or vomit
Ongoing soft stool or diarrhea

Contact your veterinarian the same day if your cat ate a worm or insect with additives, from contaminated soil, or in a large amount.

Go to an emergency clinic now for breathing trouble, repeated vomiting, a painful abdomen, drooling, tremors, weakness, or collapse.

Frequently Asked Questions

Can cats eat wax worms without getting sick?

Most cats can eat a single waxworm without getting sick. Waxworms are not toxic, but they are high in fat and are not a balanced food. The bigger risk is the container bedding or any supplement powder on the worm.

Do cats eat worms on purpose?

Some cats eat worms on purpose, and some swallow them by accident while hunting or eating grass. Cats naturally eat prey such as mice, frogs, and insects, which can carry parasite larvae [1]. You may never see it happen.

Can a cat get worms from eating a worm?

A cat can get parasites from eating prey that carries larvae, and roundworm infection is commonly linked to eating rodents with larvae in their tissues [1][2]. A plain earthworm is a lower risk than a rodent, but soil contamination still matters.

Should I deworm my cat after it eats a worm?

Not automatically. Deworming drugs are available from your veterinarian to treat infection, and the right choice depends on which parasite is present [1]. Call your vet, describe what your cat ate, and follow their advice instead of guessing.

Are worms a good source of protein for cats?

No. Worms are not a balanced protein source for cats, and they can carry parasites and bacteria. A complete and balanced cat food is the right base of the diet, and diet quality affects the gut microbiome [3]. Treats and insects should stay a small extra, not a meal.

References

Gastrointestinal Parasites of Cats - Cat Owners. Merck Veterinary Manual.
Gastrointestinal Parasites of Cats. Cornell University College of Veterinary Medicine.
Comparison of the effects of four commercially available prescription diet regimens on the fecal microbiome in healthy cats. The Journal of veterinary medical science, 2026.
Using DNA Metabarcoding and Citizen Science to Assess the Diet of Owned Domestic Cats. Ecology and evolution, 2026.
A preliminary survey of feline filarial parasites in Kerala State, India. Parasitology research, 2026.