The 4 Best Dog Dewormers of 2024

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Intestinal parasites, often called worms, are microscopic organisms that live inside your dog and silently cause harm. Common intestinal parasites in dogs include roundworms, tapeworms, and hookworms. Some worms, like roundworms and hookworms, can also infect humans. If your dog has worms, it’s important to get rid of worms in dogs quickly and safely, but choosing parasite prevention can be difficult. The best dog dewormers kill the parasites your pet already has, while intestinal parasite preventives prevent future infections. 

With guidance from veterinarians, we chose the best dog dewormers based on their safety, efficacy, number of parasites targeted, and ease of use. Our top pick for a broad-spectrum dewormer is Drontal Plus Taste Tabs. One dose can kill four types of intestinal parasites, which is more than any other treatment.

Before you begin treatment, your veterinarian should do a fecal test to determine what type of worms your dog has. Your vet can advise you on what product might be best depending on your dog’s temperament, lifestyle, and the most common parasites where you live since some products also kill fleas, ticks, and heartworms. All of the treatments we recommend also require a prescription from your veterinarian.

Learn more about how Insider Reviews tests and researches pet products.

Our top picks for the best dog dewormers

Best broad-spectrum dewormer for dogs: Drontal Plus Taste Tabs – See at Chewy

Best tapeworm dewormer for dogs: Droncit Tablets – See at Chewy

Best oral parasite preventive for dogs: Trifexis Chewable Tablets – See at Chewy

Best topical parasite preventive for dogs: Advantage Multi for Dogs – See at Chewy

Best broad-spectrum dewormer

Drontal Plus is our top pick for the best dog dewormers because it eliminates multiple types of parasites in one dose and within seven days. You can give your dog the flavored chewable tablet alone or with a small amount of food.

The broad-spectrum dewormer contains three powerful active ingredients: pyrantel pamoate, praziquantel, and febantel. These ingredients work together to cover four species of tapeworms, two species of hookworms, two species of roundworms, and whipworms.

You’ll need a prescription for Drontal Plus from your veterinarian, and a vet visit is also important because your dog may have other parasites that even a broad-spectrum dewormer can’t eliminate. Keep in mind that your dog may require one or more follow-up treatments to make sure all the worms are eliminated. And because dogs commonly become infected with tapeworms by ingesting fleas, you’ll also want to control and prevent those with one of the best flea and tick treatments for dogs. 

Best for tapeworms

One Droncit tablet works to paralyze and eliminate the four most common species of tapeworms within 24 hours. The active ingredient in Droncit is praziquantel, which is safe and effective for adult dogs and puppies 4 weeks of age and older. You can feed your dog the tablet whole or crumble and mix it with food.

Droncit is conveniently and affordably sold per pill, unlike the other tapeworm medicine we considered, Elanco Tapeworm Dewormer, which contains the same active ingredient praziquantel but is only sold in a five-pack. To prevent future tapeworm infections, be sure to treat any fleas your dog may have and give them a monthly flea prevention medicine.

Best oral parasite preventive

Our pick for best oral parasite preventive is Trifexis, a chewable tablet you give your dog monthly to treat and control hookworms, roundworms, and whipworms. It also kills adult fleas and prevents heartworm. For maximum effectiveness, you should give your dog the beef-flavored chewable tablet with food.

Trifexis uses spinosad and milbemycin oximeto prevent, treat, and control parasites. While it does not kill or treat tapeworms, it kills adult fleas, which are responsible for transmitting the parasite. You’ll need a prescription for Trifexis from your veterinarian and a current negative heartworm test. It should be used with caution in dogs with a history of seizures or breeding females. And although it is safe for puppies as young as 8 weeks old and weighing at least 5 pounds, puppies less than 14 weeks of age might experience a higher rate of vomiting than older dogs. 

Because Trifexis kills adult fleas, which can transmit tapeworms, it ranked higher than preventives that do not, including Heartgard Plus, Interceptor Plus, Iverhart Max Soft Chews, and Sentinel Spectrum. Simparica Trio treats, controls, and prevents more parasites than any other oral product, including adult fleas, flea larvae, ticks, heartworms, hookworms, roundworms, mange mites, and chewing lice. However, because intestinal parasites are the primary consideration in this guide, Trifexis gets the nod for preventing three intestinal parasites compared to Simparica Trio’s two.

Best topical parasite preventive

No single preventive covers every parasite that could harm your dog, but Advantage Multi comes close. Containing the active ingredients imidacloprid and moxidectin, the topical treatment prevents three common intestinal parasites: roundworms, hookworms, and whipworms. It also prevents flea infestations by killing adult fleas before they can lay eggs and prevents heartworm and mange mites.

Choosing between an oral or topical parasite product can be a tough decision. Sometimes, dogs do better with one versus the other. “Some animals can’t tolerate or have a food allergy to an oral product, so they must use a topical,” says Dr. Melissa Smits, a partner at Fort Morgan Veterinary Clinic. “Or their skin may be sensitive to a topical so an oral is better.” If your dog has no tolerance issues, it usually comes down to your preference.

Advantage Multi is easy to use: You apply it every 30 days to the skin at the base of your dog’s neck between the shoulder blades. The liquid is absorbed and dries within hours. Unlike with some other topical preventives, you do not need to wear gloves to apply it. If you get the product on your hands, simply wash them with soap and water. For the first 30 minutes after application, keep dogs from licking the application site, either on themselves or other treated dogs in the house. Children should not touch the application site for two hours after application.

 As with all medications that prevent heartworm, your dog needs a heartworm test before starting Advantage Multi and annually after that.

How we selected the best dog dewormers

While researching and writing this guide, I drew from my eight years of experience as an assistant in veterinary hospitals and two decades of experience as a writer and editor in the pet and veterinary fields. I conducted research using the Quick Product Reference Guide published by the independent, nonprofit Companion Animal Parasite Council. This helpful reference, which includes all FDA- and EPA-approved parasite control products for small animals, lists each product’s active ingredients, how the product is used, and which parasites it controls. 

I also consulted with two licensed veterinarians for advice regarding the treatment and prevention of intestinal parasites like tapeworms, roundworms, and hookworms, as well as heartworms and ectoparasites like fleas, ticks, and mites. Although this information guided our product selection, our experts did not specifically endorse or recommend any of the products in this guide.

Here are the main attributes I looked for:

• Safety and efficacy: Only FDA-approved products were considered for this guide.
• Number of parasites treated: In general, products that covered more parasites received higher ratings. This did not apply to tapeworm dewormers, which are only intended to treat one parasite.
• Ease of use: Products received lower ratings if they were more complicated to use than a similar product. For example, lower ratings were given if gloves need to be worn to apply the product or if children and pets need to be kept away from the treated animal for a period of time after application.
• Minimum age and weight: When comparing similar products, higher scores went to preventives that can be used in younger animals.

Dog dewormer FAQs

What is the most effective dewormer for dogs?

Although different parasite preventives cover many different parasites, no one product covers every single internal and external parasite that could affect your dog. Talk to your veterinarian to help you decide which product will be best for your dog. “This is the most important part of having a relationship with a veterinarian in your area,” says Smits. “We are trained to know what parasite problems we have in our area are, what lifestyle risks are important to consider, and overall, what is best for an individual pet and lifestyle.”

Can I deworm my dog myself?

Even though some dewormers are available without a prescription, do not skip the vet visit since different drugs treat different worms. Your vet will perform a physical exam and a fecal test to determine what type of worms they have. “Not all intestinal parasites are created equal, and there is not a one-size-fits-all when it comes to deworming medications,” says Dr. Kelley Lay, a relief veterinarian in Nashville, Tennessee. Although a broad-spectrum dewormer kills several different types of worms, certain single-celled microscopic parasites (protozoa), including coccidia and Giardia, are not true worms. They require different prescription medications to treat them. Your dog also might need follow-up deworming and another fecal exam to ensure no parasites remain.

Do natural dewormers work for dogs?

Natural dewormers aren’t necessarily a better option, so you should check with your veterinarian before giving one to your dog. “While ‘natural’ deworming products may have some effect on intestinal parasites, I’ve consulted with numerous clients over the years who have tried them with repeated failure,” says Lay. She adds that conventional, veterinarian-recommended dewormers have gone through stringent drug trials and studies to prove they are effective and safe to use.

What can I give my dog to prevent worms?

Veterinarians recommend keeping dogs on a broad-spectrum parasite preventive all year, not only in the spring and summer months. Different parasites are active during different months, and parasite activity varies. Parasites can also become active earlier than expected, including during the winter. “Many adult dogs may be asymptomatic carriers,” says Lay. “Parasites are not always able to be seen in feces and so you may not even know the problem is there. This can lead to infections that linger undetected for a long time.”

Types of worms and their signs and symptoms

Most dogs will contract intestinal parasites at some point in their lives. Some of the most common worms seen in dogs are roundworms, tapeworms, hookworms, and whipworms. In adult dogs, parasite infestations may cause mild to moderate digestive symptoms like vomiting, diarrhea, and gas. However, heavy infestations can lead to severe issues, especially in young puppies.

“They can cause intestinal problems, malnutrition, anemia, growth problems in puppies, and even potential autoimmune issues,” says Smits. “Also important is the zoonotic risk, potential spread to human family members.”

• Roundworms: These parasites are common in dogs, especially puppies, and are 3- to 6-inches long, smooth, and round-bodied. You might not know your dog has roundworms, particularly if they have only a few. In puppies, large numbers of worms may cause a pot-bellied appearance, vomiting, diarrhea, low appetite, dull coat, and restricted growth. You might also see roundworms in your dog’s stool or vomit. Roundworms are zoonotic, which means they can be spread to human family members.
• Tapeworms: Dogs pick up tapeworms when they ingest an infected adult flea. As the tapeworm grows, segments break off and pass in your dog’s stool. If you see something in your dog’s feces that resembles grains of white rice or you notice them licking or biting the area under their tail, they could have a tapeworm infestation.
• Hookworms: Hookworms are blood-sucking parasites that attach to the wall of the intestines. These tiny worms are nearly invisible without the assistance of a microscope. Signs of hookworm infection in dogs include anemia, weight loss, bloody diarrhea, dull coat, and growth restriction. Hookworms are zoonotic so they can be spread to human family members.
• Whipworms: Whipworms are relatively large intestinal parasites (about a ¼-inch long) that reside in the cecum and large intestine, where they wreak serious havoc. Dogs with heavy whipworms are likely to experience concerning symptoms, such as watery, bloody diarrhea, weight loss, and anemia.