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Can Cats Eat Worms (Earthworms)? Vet Approved Facts & Safety Tips

Written by: Beth Crane

Last Updated on April 12, 2024 by Nicole Cosgrove

earthworms up close

Can Cats Eat Worms (Earthworms)? Vet Approved Facts & Safety Tips


Dr. Karyn Kanowski Photo


Dr. Karyn Kanowski

Veterinarian, BVSc MRCVS

The information is current and up-to-date in accordance with the latest veterinarian research.

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Cats are carnivores by nature, and they’ll chase after and hunt any animal they can when they’re outside. This includes even the smallest, most unlikely of prey, such as earthworms! Cats are opportunistic hunters who’ll eat any small creature if it’s a viable source of nutrition, and if your cat comes across an earthworm, they may eat it. 

Although cats can eat earthworms, it’s wise to stop them from doing it as much as you can. Earthworms can carry parasites that cause disease in cats, so preventing them from ingesting earthworms is the best course of action. 

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Are Earthworms Bad For Cats? 

Earthworms aren’t toxic to cats, but they’re not the best things for them to eat, either. Earthworms only provide your cat with a little protein, and there are nasty parasites that can be transferred from the worm to your cat. Capillaria is a parasite your cat can pick up from earthworms, and they can cause problems in many organs of the body. 

Photo Credit: sarahharding, Pixabay


Infections of Capillaria worms, often Capillaria plica, in cats cause Capillariasis. This species of parasitic worm has a complex life cycle that begins with eggs being deposited into the soil via the urine of infected cats. These then hatch into larvae that are ingested by earthworms. Once ingested, the larvae will mature in the earthworm until they’re able to infect a new host.


Once a cat eats an earthworm infected with a Capillaria worm, the worms will mature and move to the bladder. Eggs are shed into the urine, which then starts the life cycle again. There are several signs Capillaria worms can cause, but many cats don’t show any visible signs at all. 

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  • Painful urination (dysuria)
  • Having to urinate more often or frequently (pollakiuria)
  • Straining to urinate (stranguria)
  • Blood in the urine (hematuria)

Cats can have similar signs for different urinary problems, like bladder stones or crystals. It’s crucial to take your cat to the vet if they seem unwell. 

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What Happens If My Cat Eats an Earthworm?

If your cat eats an earthworm, the likelihood is that they’ll be fine! Because earthworms aren’t toxic, they’ll likely not cause a problem. However, there’s a chance that any earthworms they eat could carry Capillaria or other infectious parasites, such as roundworm eggs. 

Earthworms move through soil where roundworm eggs can be found, but they don’t spread them directly. If you notice your cat eating an earthworm or notice any signs of ill health, you should seek the advice of your vet. Your vet can tell you whether your cat needs to see them and can advise you of any signs to look out for. 

vet checking bengal cat
Photo Credit: Pressmaster, Shutterstock

Why Do Cats Eat Earthworms?

Cats are hunters that chase and consume prey. Outdoor cats may be on the prowl and consider an earthworm a quick and juicy snack, but they don’t provide much in the way of nutrients. In most cases, domestic cats will eat earthworms simply because they’re playing with them, rather because they’re hungry. Although pet cats don’t generally need to hunt for food, the hunting instinct is still there.

How Can I Stop My Cat Eating Earthworms?

The only reliable way to prevent your cat from eating earthworms is to stop them from going outside. Earthworms only usually come up from underground after it rains, as the topsoil is easier to move through when wet. However, you cannot guarantee there won’t be any on dry ground, so there’s always the chance your clever cat could find one! But really, there’s no real need to stop them. In most cases, your cat will have no ill effects of eating earthworms, and most routine worming treatments will eradicate any parasites.

A catio can help keep your cat safe from eating earthworms, getting sick or attacked by predators, and hunting other animals. Catios can give your cat the freedom to enjoy the fresh air while keeping them enclosed and protected. 

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Final Thoughts

Cats are natural hunters that play with and eat many creatures. Earthworms are a relatively novel experience for many cats, particularly if they don’t get outside much! They’re wriggly and easy to catch, so your cat might decide to sample one to see what it’s like. 

Earthworms aren’t toxic to cats and will most likely cause them no harm. However, they can carry Capillaria worms and other parasite eggs due to their movement through the soil. Provided that your cat is up to date with their preventative health treatments, there is likely no cause for alarm, but if in doubt, always speak to your vet. 

Featured Photo Credit: Bukhta Yurii, Shutterstock

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