Outdoor cats and those who are routinely exposed to soil where other animals defecate are prone to worms. Kittens and cats who do not receive regular preventative health care are most at risk for developing complications associated with internal parasites.

Common Types of Worms in Cats

• Roundworms – the most common internal parasites in cats.
• Tapeworms – an infestation can cause vomiting or weight loss. Cats acquire tapeworms by ingesting an intermediate host, like an infected flea or rodent. When cats are infected, tapeworm segments—actual pieces of the worm that resemble grains of rice—can often be seen on the fur around a cat’s hind end.
• Hookworms –  reside primarily in the small intestine. Because they feed on an animal’s blood, hookworms can cause life-threatening anemia, especially in kittens.
• Lungworms – reside in the lungs of a cat. Most cats will not show any signs of having lungworms, but some can develop a cough.

Symptoms of Worms in Cats

Symptoms differ depending on the type of parasite and the location of infection, but some common clinical signs include:

• Diarrhea
• Worms visible in stool or segments of worm seen near anus
• Bloody stool
• Bloating or round, potbellied appearance to abdomen
• Weight loss
• Vomiting
• Constipation
• Anemia
• Coughing
• Trouble breathing

If you think your cat may have worms, it’s important to bring her to a veterinarian, who can confirm the presence of worms. Avoid self-diagnosis, since worms are not always visible or identifiable.

Treatment for Worms in Cats

Treatment options include injection, oral, or topical medication. But because cats almost always get tapeworms as a result of swallowing a flea, be sure to handle any flea problems your cat has before tackling tapeworms.

Please don’t attempt to treat your pet yourself— some over-the-counter deworming medications can be harmful if used inappropriately.

Not all dewormers eradicate all types of worms, your cat should be treated for the specific type of worms he has. Your veterinarian will determine the type of worm(s) infestation(s) your cat has, and prescribe the best course of treatment. Your veterinarian will also be able to tell you if the dewormer should be repeated, and when.

Not all dog medications are safe for cats.
Some over-the-counter deworming medications can be harmful if used inappropriately.

Worm Prevention

Keep your cat indoors to avoid exposure to infected cats, rodents, fleas and feces.
Make sure your home, yard and pets are flea-free.
Practice good hygiene and wear gloves when changing cat litter or handling feces. It’s also important to frequently dispose of stool.

Ask your veterinarian to recommend an appropriate internal parasite treatment or prevention program for your cat.

Transmission of Worms from Cats to Humans

A large number of roundworm eggs can accumulate where cats defecate. People, especially children, who ingest such eggs can develop serious health problems, such as blindness, encephalitis and other organ damage. Treatment of blindness caused by roundworm may involve surgical removal.

Hookworm larvae can penetrate human skin and cause lesions. People can acquire tapeworms through the ingestion of an infected flea, although this is rare.