Roundworms

Roundworms are the most common of the parasitic worms found inside a cat (or dog). Almost all cats become infected with them at some time in their lives, usually as kittens. Roundworms may be contracted in different ways, making them easy to spread and hard to control.

Your cat may take in (ingest) infective roundworm eggs from the area where it lives or by eating mice or other small animals ("hosts") carrying young worms (larvae). Infection in kittens may also occur through the mother's milk.

How will roundworms affect my cat?

Adult roundworms live in the cat's intestines. Most cats will not have signs of infection; however, cats with major roundworm infections commonly show vomiting, weight loss, dull hair, and a potbellied appearance. The cat may cough if the roundworms move into the lungs.

You may notice adult roundworms in your cat's feces or vomit. They will appear white or light brown in color and may be several inches long.

How do I prevent my cat from getting roundworms?

Because roundworms can enter your cat's body in many different ways, it is essential to keep your cat's living area clean (regular cleaning of the litter box) and, if possible, keep your cat indoors to prevent it from eating wild animals that may carry roundworms.

Kittens should be treated for roundworms every 2 weeks between three and nine weeks of age and then receive a preventive treatment monthly.  Fecal (stool) examinations should be conducted 2 to 4 times during the first year of life and 1 or 2 times each year in adults. Nursing mothers (queens) should be kept on monthly preventive and treated along with their kittens. A monthly parasite control product effective against roundworms is recommended to treat potential new infections. Many heartworm medications also control roundworms so ask your veterinarian about prevention and treatment choices.

Can humans be harmed by roundworms?

Roundworms do pose a significant risk to humans. Contact with contaminated soil or feces can result in human ingestion and infection. Roundworm eggs may accumulate in significant numbers in the soil where pets deposit feces. Children should not be allowed to play where animals have passed feces. Individuals who have direct contact with soil that may have been contaminated by cat or dog feces should wear gloves or wash their hands immediately.

For veterinary professionals, more detailed information on roundworms can be found at https://www.capcvet.org/guidelines/ascarid/.

Did you know?

  • People can get roundworms from contact with feces or contaminated soil. Children and pregnant women are especially at risk.
  • Cats can get roundworms by eating wild animals as well as from feces or a contaminated environment.
  • Most cats are infected with roundworms at some point in their life. They often show no symptoms.
  • If your cat suffers weight loss, dull hair, and a potbellied appearance, it may have a major roundworm infection. You may see roundworms in your cat's feces or vomit.
  • Your veterinarian can help you with roundworm prevention, examination, and treatment.
  • Other kinds of worms that cats can get include heartworms, hookworms, and tapeworms.

Ask Your Veterinarian

About Roundworm Preventio

It may not be obvious even if your kitten or cat has roundworms, and yet people can be infected by them. For this reason, it is a good idea to have a regular program of preventative treatment starting with kittens at three weeks of age. Cats should have fecal (stool) exams 2 to 4 times in their first year of life and once or twice a year thereafter. The best way to control roundworms is to be sure to be sure to use a parasite control product recommended by your veterinarian every month.