Roundworms in Cats: The Parasite Almost Every Kitten Meets

In this guide

This is the most common intestinal parasite in cats, and it usually starts before a kitten ever opens its eyes.

If there is one intestinal parasite nearly every cat encounters at some point, it is roundworms. They are so widespread in kittens that many vets treat for them as a matter of routine, well before symptoms would ever appear.

What Roundworms Are

Roundworms, most commonly Toxocara cati, are long, spaghetti-like worms that live in the small intestine, feeding on partially digested food rather than blood. Adult worms can grow several inches long and are sometimes visible in vomit or stool during a heavy infection.

How Cats Get Them

• Nursing: Kittens very commonly pick up roundworm larvae through their mother's milk, which is why deworming often starts as early as two to three weeks of age and is repeated over several rounds.
• Contaminated soil or litter: Roundworm eggs can survive in soil for a long time, and cats that dig, hunt or use outdoor areas frequented by other cats can ingest eggs while grooming their paws.
• Eating infected prey: Rodents and birds can carry roundworm larvae in their tissue, so hunting cats pick up infections this way too.

Signs of Infection

• A swollen, pot-bellied appearance, especially noticeable in kittens
• Vomiting, sometimes with visible worms
• Diarrhoea
• Dull coat and poor growth in kittens
• General lack of energy

Light infections in adult cats often cause no obvious symptoms at all, which is another reason routine deworming matters rather than waiting for visible signs.

The Human Angle

Roundworms are zoonotic, meaning they can pass to people, most often children, through accidental ingestion of eggs from contaminated soil or sandpits. In rare cases the larvae migrate through body tissue, a condition called visceral larva migrans, or, less commonly, into the eye, called ocular larva migrans, together known as toxocariasis. This is not a reason to worry unduly, but it is a good reason to wash hands after gardening or after cleaning a litter tray, keep sandpits covered when not in use, and deworm cats on a regular schedule, all of which sharply reduce the risk.

Treatment and Prevention

Roundworm infections are treated with a straightforward deworming medication, usually repeated after two to three weeks to catch any larvae that were not yet mature enough to be killed by the first dose. Kittens typically follow a set deworming schedule through their first few months, and adult cats generally benefit from deworming every three to six months depending on their lifestyle and risk of exposure, which your vet can help tailor to your cat specifically.

Article content © Ravi Teja. All rights reserved.