Moderate severity

Roundworms

Long, spaghetti-like intestinal worms, extremely common in kittens, which can be passed on through the mother's milk. Heavy burdens sap growth and condition and, occasionally, pose a risk to people.

⚠️ Common symptoms

A pot-bellied, bloated look, especially in kittens, despite a poor overall conditionA dull coat, slow growth or failure to thriveOccasional vomiting, sometimes bringing up a spaghetti-like wormDiarrhoea or a generally upset tummyOften no visible signs at all in a lightly infected adult cat

Roundworms are the most common intestinal parasite of cats, pale and rounded and, when passed, unmistakably like a tangle of moving spaghetti. They live free in the small intestine, feeding on the partly digested food passing through, and the females shed enormous numbers of tough, microscopic eggs into the droppings — eggs that can survive in soil and around the home for a very long time, seeding fresh infections long after the original cat has gone.

What makes roundworms such a problem in the very young is the way they spread. Larvae can lie dormant in an adult female cat's tissues and reactivate during pregnancy and nursing, passing to the kittens through the milk, so a litter is often infected almost from birth. That is why the classic patient is a kitten with a swollen, pot-bellied tummy, a staring coat and disappointing growth, sometimes vomiting up an actual worm. Adult cats usually cope with a light burden showing few or no signs, but they keep quietly shedding eggs into the environment.

Treatment is straightforward with a suitable wormer, but a single dose is rarely the whole answer: worming kills the adult worms present, not the larvae still migrating through the body, so kittens and nursing queens are wormed repeatedly on a schedule set by the vet. Alongside the medicine, prompt litter-tray hygiene and stool removal keep the environmental egg load down. Roundworms also matter beyond the cat: their larvae can, uncommonly, cause disease in people, particularly children, which makes routine worming and good hand-washing a matter of family health as much as feline welfare.

🔍 Causes

  • Kittens infected through their mother's milk, the commonest route of all
  • Swallowing microscopic worm eggs from a contaminated environment
  • Hunting and eating infected prey such as rodents
  • A nursing queen passing on larvae that reactivate during pregnancy and feeding

🛡 Prevention

Follow your vet's deworming schedule, which is more frequent for kittens and nursing mothers than for settled adult cats, and worm hunting cats regularly since prey is a constant source. Pick up and dispose of stools promptly to reduce egg build-up in the environment, keep litter trays clean, and wash hands after handling cats or cleaning trays — a sensible habit given roundworms can, rarely, affect people.

💊 Treatment

Roundworms respond well to routine deworming, and most broad-spectrum wormers from your vet treat them effectively. Kittens need worming on a regular schedule from a few weeks of age, repeated at intervals because the treatment kills the worms present but not those still developing or migrating through the body. Your vet will advise the right product and timing by age and weight, and a follow-up dose is usually part of the plan rather than a single treatment.

When to see a vet: See a vet for a pot-bellied, poorly growing or vomiting kitten, and any time you see a worm passed in vomit or stools, so the right wormer and schedule can be set up. Adult cats generally just need routine worming, but book a check if there is persistent diarrhoea, weight loss or a stubbornly dull coat that better parasite control does not resolve.

⚕️ Medical disclaimer

  • This information is educational only and is not a substitute for veterinary advice.
  • Symptoms overlap between conditions — only a vet can diagnose accurately.
  • Never withhold treatment or self-medicate based on information found online.
  • When in doubt, call your vet. Early intervention almost always leads to better outcomes.

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