Worming Cats: How Often, Which Wormer, and Why It Matters
How often to worm your cat, which worms they can catch, the signs to watch for, and how to keep on top of treatment all year round.
Worming is one of those quiet bits of cat care that's easy to forget — until you spot something wriggling. The reassuring news is that intestinal worms are very common, rarely an emergency when treated promptly, and straightforward to prevent with a simple routine. Most cats will encounter worms at some point in their lives, and a sensible, regular treatment plan keeps the problem firmly under control. This is general guidance, not a substitute for veterinary advice — if you're worried, contact your vet.
What worms can cats catch?
In the UK, cats most commonly pick up roundworms and tapeworms. Roundworms are spaghetti-like and especially common in kittens, who can get them through their mother's milk before they're even weaned. Tapeworms are flat and segmented — you may spot small rice-like segments around your cat's bottom or in their bedding, and these are often linked to fleas, which cats swallow while grooming. Less commonly, cats can pick up lungworm or hookworm.
Understanding the difference matters because no single wormer covers everything in every situation. Roundworm and tapeworm need different active ingredients, which is one reason it's worth getting the right product for your cat rather than grabbing the first treatment on the shelf. Your vet can tell you which worms are most relevant for a cat with your cat's particular lifestyle.
How do cats get worms?
Cats catch worms in several everyday ways: hunting and eating prey such as mice and birds, swallowing fleas during grooming, contact with infected faeces, or (for kittens) through their mother. Outdoor cats and keen hunters are at higher risk, but indoor cats aren't immune — fleas and the odd mouse find their way indoors too, and even a houseplant or a pair of shoes carried in from outside can bring eggs into the home.
There's also an important link between fleas and tapeworm: when a cat grooms and swallows an infected flea, it can develop a tapeworm. That's why flea control and worming go hand in hand, and treating one problem without the other often means the issue keeps returning.
Signs your cat may have worms
Many cats with worms show no obvious signs, which is exactly why routine treatment matters. When signs do appear, they can include:
- Visible worms or rice-like segments around the bottom, in faeces or bedding
- A dull coat or pot-bellied appearance (especially in kittens)
- Weight loss despite a normal appetite
- Vomiting or diarrhoea
- Scooting or excessive licking under the tail
How often should you worm your cat?
This depends on your cat's lifestyle, so there's no single answer that fits every cat — your vet can tailor a plan. As a general guide, many UK vets recommend worming hunting or outdoor cats more frequently than indoor-only cats, because every mouse or bird is a fresh source of infection. Kittens need a specific schedule from a young age, as roundworm is so common in the very young. Always weigh your cat and use a product licensed for their exact weight, following the packaging precisely — under-dosing may not work, and over-dosing risks side effects.
It's easy to lose track of when treatments are due, especially in a busy household. Our parasite risk assessment gives you a quick, tailored steer on how often your cat likely needs worming based on their lifestyle, and the pet medicine calendar helps you log treatments and set reminders so none get missed.
Choosing and giving a wormer
Wormers come as tablets, liquids and spot-on treatments, and the best choice often depends as much on which your cat will tolerate as on which worms you're targeting. Tablets can be hidden in food or given with a pill-giver; spot-ons applied to the back of the neck suit cats who refuse pills. Because fleas and tapeworms are linked, treating both together is often sensible — see our guide on how to get rid of fleas on cats.
Buy a product appropriate for your cat's weight and age; if you're unsure which to choose, your vet or a registered pharmacist can advise, and prescription-strength options are available through the vet. Never use a dog wormer on a cat unless a vet has told you to, as some ingredients in dog products are dangerous for cats. You'll find cat-safe grooming and care kit in the shop.
When to see a vet
Contact your vet if:
- Your cat is losing weight, off their food, or has ongoing diarrhoea or vomiting — see why is my cat being sick and cat not eating
- You see blood in the faeces
- A kitten seems unwell or has a swollen tummy
- Worms persist despite treatment, or you're unsure which product is right
Heavy worm burdens can make kittens and older cats genuinely poorly, so don't wait if your cat seems unwell. You can find a vet near you in our directory.
Sources
- PDSA — Worms in cats: https://www.pdsa.org.uk/pet-help-and-advice/pet-health-hub
- Blue Cross — Cat health advice: https://www.bluecross.org.uk/advice/cat
- International Cat Care — Cat advice: https://icatcare.org/advice/
Common questions
How often should I worm my cat?
It depends on lifestyle — hunters and outdoor cats usually need worming more often than indoor cats, and kittens follow a specific schedule. Your vet can set a plan; our parasite risk assessment gives a quick personalised steer.
Can I catch worms from my cat?
Some cat worms can, rarely, affect people, which is why routine worming and good hygiene (washing hands, scooping litter regularly) matter — especially in homes with young children. Speak to your vet or GP if you have concerns.
Do indoor cats need worming?
Yes, though usually less often than outdoor cats. Fleas and the occasional mouse can still bring worms indoors, so a periodic treatment is wise. Your vet can advise the right frequency for an indoor cat.
Can I use a dog wormer on my cat?
No — never give a cat a dog product unless your vet has specifically told you to, as some ingredients can be harmful. Always use a wormer licensed for cats and dosed for your cat's weight.
About the author
Matt — founder, Giddy Pets
Matt started Giddy Pets to make getting pets the good stuff simpler and fairer. Everything in these guides comes from real life with pets and a lot of trial and error — it's practical guidance, not veterinary advice. If a guide gets something wrong, tell him directly.
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