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How Long Does it Take for A Cat Dewormer to Work?

Parasitic worms plague pets of all kinds. The severity of any infestation depends on both your pet and the worms that threaten his or her health. Some worms cause symptoms that are only mildly uncomfortable while others can pose serious health risks. Roundworms, tapeworms, and heartworms each infect different parts of your pet and the differences in their biology mean that they have different vulnerabilities. Because not all worms are created equal, different infestations require different treatments.

These treatments use different methods of action to ensure their efficacy, meaning that some dewormers will work more quickly than others. Further variety is available because multiple formulas can effectively treat the same types of worms with different active ingredients. The rest of this article will discuss some of the more popular treatments for worms that commonly affect cats and the typical administration period of these products.

Treat Your Pet's Worms

When a cat is suffering from an apparent illness, itís important to seek out treatment quickly; however, it is crucial to identify the source of an infestation before attempting to treat it. Firstly, only cats that are confirmed to have worms should undergo the deworming process, as the poison used for killing worms can negatively affect your cat. Additionally, the type of worm affecting your cat should properly be identified before you or your veterinarian try to treat it.


Roundworms are one of the most common intestinal parasites found in cats, which is why itís so important for cat owners to be aware of the signs and symptoms of an infection such as a swollen abdomen, weakness, and loss of appetite.

Because these parasites are contracted through ingestion of roundworm eggs, they can be easily prevented by keeping your catís living area clean and having them indoors if possible. Regular visits to the vet are also helpful to make sure your feline is parasite-free, especially when your cat is nursing kittens.

Despite how troublesome they are, treating roundworms is relatively easy through oral medications like SENTRY Worm Away for Cats, which uses magnesium stearate to kill any roundworms present in your cat's system. These capsules work over a period of 2-3 weeks, with the slight possibility of requiring re-treatment. The Excel Roundworm De-Wormer also works efficiently to the same end with piperazine as its central ingredient. Though this treatment takes the same amount of time to work as SENTRY Worm Away, this dewormer is a viable alternative for cats who cannot take magnesium stearate.


Mosquitoes play a key role in spreading heartworms to your precious pets. When a mosquito takes a bite from an infected animal, it also picks up baby heartworms with the blood and transfers them into the next victim.

Heartworm disease is more threatening to cats than dogs because prevention is the only means of protection for felines. Although there are many heartworm medications for dogs, they cannot be used in cats. Furthermore, signs of heartworm disease can be subtle or dramatic, making it difficult to catch. That is why it is absolutely essential that you take your kitty to the vet on a regular basis and take extra steps to keep them protected with mosquito repellent and/or a heartworm preventive, especially in the summer months.


Tapeworms are transmitted by fleas, making them another common parasite in cats. Fleas ingest the parasite eggs and transfer them into your cat when they bite. Tapeworms hook onto your catís small intestines, robbing your furry friend of nutrients. Because of their nature, they can be dangerous to your pet in large numbers and cause them to drop to an unhealthy weight.

If youíre working to control a flea infestation on your cat, they are at extremely high risk of being infected by tapeworms. Get your kitty checked out by your veterinarian and keep a close eye out on symptoms of tapeworms such as mild diarrhea, appetite changes, weight loss, and segments of the tapeworms in the feces. The best way to prevent a tapeworm infestation is to stay vigilant with flea control alongside keeping the catís living areas clean.

Tapeworms can be treated with tapeworm tabs like Drontal and Bayer Tapeworm Dewormer for Cats, which use an anthelmintic called praziquantel. These tabs require only a single administration to start working and effectively eliminate tapeworms within 3 weeks; although, some cats may require another 2-3 week period of treatment.

Other Considerations

Allergies or other medical information provided by your veterinarian can make one treatment more effective for your cat. Ask your veterinarian for a recommendation to help determine which treatments are right for you and your pet. Most dewormers will fall in line with those mentioned in this article, requiring an initial period of only 2-3 weeks to eliminate worms; however, some treatments will also require a second dosage to eradicate the second wave of parasites.

Aside from roundworms and tapeworms- other parasitic worms can pose a more serious threat. Heartworms, for example, can only be treated with a prescription medication. Just like with non-prescription medications, you should ask your veterinarian if they have any specific recommendations for your pet when selecting prescription dewormers. Has your pet ever had worms? Which treatment worked for you and how long did it take? Leave your answers in the comments and let us know!

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