Roundworm Medication for Cats

Parasite control helps keep your kitty healthy.
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If your kitty gets roundworms, they can grow up to 7 inches long in her intestines and cause her many problems. Symptoms include vomiting and diarrhea, and sometimes coughing and even pneumonia. The good news is that roundworms are typically easy to treat in cats of all ages.


Your cat can get roundworms from coming into contact with eggs in the soil, even years after other cats left them there. She can also get them from eating an infected rodent. Kittens often get them from mom when they nurse. It’s even possible for you to get roundworms from your cat -- and it can create serious problems if these worms migrate to certain parts of your body, such as the eye, where it can cause complete or partial blindness. Good sanitation, especially washing your hands, helps to minimize your risk. Keeping your kitty dewormed virtually eliminates chances of you picking up this parasite.

Pyrantel Pamoate

Pyrantel pamoate is the active ingredient in many pet dewormers, and it is highly effective against roundworms. It works by making the mature worms lose their grip on your cat’s intestines, and they end up passing out of her body along with the feces. They’re usually still alive and wiggling when this happens, but they don’t live long outside of the host so they’ll die soon after being expelled. Pyrantel pamoate can be given to kittens as young as 2 weeks. It won’t kill worm larvae, so it has to be administered again about two to four weeks after the first deworming.

Milbemycin Oxime

Milbemycin oxime kills roundworms, hookworms and some whipworms as well as the larval stage of heartworms. Pets are often placed on this medication as a heartworm preventive, and the fact that it controls other types of worms is an added benefit. You’ll need to get milbemycin oxime from your vet, and he’ll check your cat for the presence of heartworms before you give her the drug. You can’t give it to cats younger than 6 weeks old or weighing less than a pound and a half. Once on the medicine, your kitty will need a dose once every 30 days.


If you’re not too keen on cramming a pill down your kitty’s throat, you might want to try selamectin. This medication is applied topically by squirting the proper dosage at the base of your cat’s skull. It kills fleas, roundworms, hookworms, ear mites and heartworms by damaging their nervous systems. You can’t use it on kittens younger than 8 weeks old, and for pets that are old enough you have to apply it once per month. Regular use will make sure none of these pests is able to do any real harm to your cat.

Always check with your veterinarian before changing your pet’s diet, medication, or physical activity routines. This information is not a substitute for a vet’s opinion.

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