8 Signs Your Cat Might Have Worms (and What Actually Helps)

Cats are good at hiding when something's off. A cat with a sore tooth still eats. A cat with early kidney trouble still purrs on your lap. Worms are no different; by the time the signs are obvious, the infestation has usually been building for a while.

The tricky part is that intestinal parasites don't always look like a "stomach problem." Sometimes it's a coat that's lost its shine. Sometimes it's a cat who's eating like a horse but getting thinner. And because indoor cats can pick up worms too, from fleas, from a housemate cat, even from soil tracked in on shoes, "he never goes outside" isn't the reassurance cat parents think it is.

A few of these symptoms overlap with other conditions. Digestive upset and skin issues, for instance, can look a lot like food allergies. So think of this list as a reason to call the vet, not a substitute for one, a faecal test is the only way to actually confirm what's going on.

1. Diarrhoea that won't quit

A single loose stool after a diet change or a stressful day isn't cause for alarm. But roundworms and hookworms irritate the intestinal lining and mess with how well your cat absorbs water and nutrients, and that shows up as stools that are soft, watery, mucus-coated, or just off in a way you can't quite place.

Keep an eye on the litter tray for a few days if something seems different: is the mucus new, is there any blood, is your cat going more often than usual? One rough day doesn't mean worms. Diarrhoea past 24 hours, especially paired with vomiting or a cat who's gone quiet and off her food, is worth a call.

2. Vomiting, especially with visible worms

Worms irritating the gut can trigger vomiting on their own, but occasionally roundworms migrate up into the stomach and come up in the vomit itself, often described as looking like strands of spaghetti. Not pleasant, but genuinely useful information for your vet if you can describe or collect it.

Pay attention to frequency (once, or several times today?), timing relative to meals, and what's actually in it, food, bile, blood (dark and grainy usually means digested blood, bright red is fresher). Repeated vomiting dehydrates a cat fast, so don't wait it out if it's happening more than once. If you can safely scoop a sample into a container before the vet visit, do it.

3. Losing weight while eating more than usual

This is the one that throws cat parents off, because it looks backwards. Your cat seems hungrier than ever, begging at the bowl, finishing meals in record time, and yet the ribs are starting to show. Roundworms, tapeworms, and hookworms are essentially competing with your cat for the nutrients in every meal, so the body compensates with appetite while still coming up short. In kittens this matters even more, since it can interfere with normal growth.

A rough way to track it at home: weigh yourself, then weigh yourself holding the cat, and subtract. Do this monthly. If the number keeps dropping despite a full food bowl and a hearty appetite, that's a vet visit, not a "let's watch it" situation.

4. A round, firm belly on an otherwise thin cat

The classic pot-bellied look, most common in kittens, is different from a cat who just ate, it's a swelling that doesn't come and go with meals, sitting on a body that's otherwise lost condition everywhere else. Inflammation from a heavy worm burden, plus gas and fluid buildup, can genuinely swell the abdomen, and in bad cases enough worms can partially block the intestine.

If the belly feels tight or your cat flinches when you touch it, don't try to wait this one out or treat it yourself, a firm, painful, swollen abdomen has more than one possible cause, some of them urgent, and a kitten especially should be seen promptly.

5. Suddenly not much of a player

You know your own cat's baseline better than any checklist can capture. If a cat who used to chase the laser pointer for ten minutes now watches it drift by, or naps through what used to be prime zoomies hour, something's using up their energy elsewhere.

Hookworms are the main suspect here, since they feed on blood directly and can contribute to anaemia, fewer healthy red blood cells means less oxygen getting where it needs to go, which reads as genuine fatigue, not laziness. Ongoing gut discomfort from any of the worm types can also just make a cat want to be left alone. If the quietness sticks around, or shows up alongside diarrhoea, weight loss, or a rough coat, it's worth mentioning to your vet, and it helps to jot down roughly when you first noticed it.

6. Scooting or licking at the rear end

Dragging the bottom across the carpet looks funny but usually means something's itchy or uncomfortable back there, and tapeworm segments are a common cause. As the worm matures, it sheds small egg-carrying segments that pass out through the anus, hence the itch.

Check the fur around the tail and anywhere your cat sleeps for what looks like grains of rice or sesame seeds; that's the segment, dried out. If you find one, a sealed bag or small container brought to the vet makes identification much faster than a description alone. Worth noting: scooting has other causes too (impacted anal glands, for one), so it's not automatically a worm diagnosis.

7. Pale gums

This is the symptom that should move you to call today, not "this week." Healthy gums are a solid pink. Pale, white, or grey gums point to anaemia, and in cats with a heavy hookworm burden, hookworms attach to the gut wall and feed on blood, that anaemia can become serious, particularly in kittens and older cats.

Lift the lip and take a look; check the inner eyelid too if you can. Weakness, laboured breathing, or collapse alongside pale gums is an emergency, not a "mention it at the next checkup" situation, that cat likely needs bloodwork and treatment beyond a simple dewormer.

8. A coat that's lost its shine

Coat quality is often the last thing cat parents connect to worms, because it happens slowly. A cat competing with parasites for nutrients has a body that prioritises organs over fur, so the coat can go dull, dry, or coarse, sometimes with flaking skin or patchy thinning worked in over weeks.

A monthly photo in the same spot and lighting makes this kind of gradual change much easier to catch than memory alone. If the coat keeps declining, especially with any of the symptoms above, that's worth flagging at a vet visit. Once treatment sorts out the underlying cause, good nutrition can help the coat recover, though it typically takes several weeks to look normal again.

Quick reference

What comes after the dewormer

Catching these signs early is most of the battle. A proper diagnosis still has to come from your vet, though, different worms need different medications, and more than one of these symptoms can come from something else entirely.

Once treatment starts, recovery is partly about giving your cat's gut time to reset:

• Stay on a prevention schedule. Ask your vet what year-round parasite prevention makes sense for your household, especially if you've got outdoor access or multiple pets.
• Break the reinfection cycle. Scoop the litter box daily, give it a real scrub weekly, wash food bowls and bedding regularly, and don't ignore fleas, they carry tapeworms, so a flea and tick treatment for the home matters more than people expect.
• Support the gut while it heals. Consistent meals, fresh water, and good nutrition go a long way. Check with your vet before adding any supplements during recovery, particularly if your cat's on medication.

On that last point, some cat parents find a daily gut-and-oral-health routine worth keeping even after the worms are gone. Purrlys® Dental Probiotics is one option: an odourless, tasteless powder, sprinkle 1 scoop into your cat's wet food and mix well, twice daily, no brushing required. Once your cat is on the full dose (for adult cats, one 0.5 g scoop in the morning and one in the evening), most cat parents notice fresher breath within about two weeks, so allow two to four weeks from starting. Changes to plaque and gum health usually take 4 to 12 weeks from reaching the full dose and vary from cat to cat. Giving it twice a day, every day, keeps the protective biofilm strong. Once a day takes longer to show results, and some cats may not see results at all. Our dental probiotics come with a 90-day guarantee; see our refund policy for the conditions.

Worth being clear about: Purrlys isn't a dewormer and won't treat a parasite infection. If your cat is showing any of the signs above, that's a vet visit first, this is a "once things are back on track" kind of product, not a substitute for one.