The Best Dewormers for Dogs in 2025

Worms are intestinal parasites that live inside your dog, where they silently cause harm. The most common types of these microscopic organisms include roundworms, tapeworms, and hookworms. Some worms, including roundworms and hookworms, can even be passed to humans.

It’s important to treat worms quickly and safely. But with so many options, choosing the right parasite treatment can be challenging. The best dewormers for dogs eliminate existing infections, while intestinal parasite preventives help protect your dog from future ones.

With guidance from veterinarians, we chose the best deworming medications based on their safety, efficacy, the number of parasites they target, and ease of use. Our top pick for a broad-spectrum dewormer is Drontal Plus Taste Tabs. One dose can eliminate four types of intestinal parasites, more than any other treatment recommended in this guide.

Before you begin treatment, it’s important that your veterinarian performs a fecal test to identify the types of worms your dog has. They can advise you on what product might be best depending on your dog’s temperament, lifestyle, and the most common parasites in your area, because some products also help control fleas, ticks, and heartworms. All of the treatments we recommend require a prescription from your veterinarian.

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

Our top picks for the best dewormers for dogs

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 dewormers for dogs because it eliminates multiple types of parasites with one dose and works within seven days. The flavored chewable tablet is easy to give your dog. You can offer it on its own or mix it with a small amount of food.

This is a broad-spectrum dewormer that covers up to four species of tapeworms, two species of hookworms, two species of roundworms, and whipworms. Its effectiveness is due to three powerful active ingredients that work together: pyrantel pamoate, praziquantel, and febantel.

Your veterinarian will need to write a prescription for Drontal Plus. Before giving your dog this medicine, it’s important to see your vet so they can also check to see if your dog has parasites that can’t be eliminated with a broad-spectrum dewormer. One or more follow-up treatments may also be needed to fully eliminate the worms. And because dogs commonly become infected with tapeworms by ingesting fleas, it’s also important to control and prevent them with one of the best flea and tick treatments for dogs. 

Best for tapeworms

One Droncit tablet paralyzes and eliminates the four most common species of tapeworms within 24 hours. Its active ingredient, praziquantel, is safe and effective for adult dogs and puppies 4 weeks of age and older. You can give the tablet whole or crumble it and mix it with your dog’s food.

You can purchase a single Droncit tablet, making it a very affordable treatment. The other tapeworm medicine we considered, Elanco Tapeworm Dewormer, contains the same active ingredient, praziquantel, but it’s only sold in a five-pack.

To prevent future tapeworm infections, you should treat any fleas your dog may have and give them a monthly flea prevention medicine.

Best oral parasite preventive

Trifexis is a beef-flavored chewable tablet you give your dog monthly to treat and control hookworms, roundworms, and whipworms. It’s our top pick for this category because it also kills adult fleas and prevents heartworm. For it to be most effective, you should give your dog the tablet with food.

Trifexis uses spinosad and milbemycin oxime to prevent, treat, and control parasites. While it doesn’t eliminate or control tapeworms, it does kill adult fleas, which transmit the parasite.

Before starting your dog on Trifexis, you’ll need a prescription 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. Although it’s safe for puppies as young as 8 weeks old and weighing at least 5 pounds, puppies under 14 weeks are more likely to experience 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 this guide is focused on intestinal parasites, Trifexis gets the nod. It prevents three intestinal parasites, compared to two covered by Simparica Trio.

Best topical parasite preventive

No single preventive covers every parasite that could harm your dog, but Advantage Multi comes close. The topical treatment prevents three common intestinal parasites (roundworms, hookworms, whipworms) with the active ingredients imidacloprid and moxidectin. It also treats 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. Or their skin may be sensitive to a topical, so an oral is better,” says Dr. Melissa Smits, who was a partner at Fort Morgan Veterinary Clinic at the time of our interview. If your dog doesn’t have any 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 don’t 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 dogs that have been treated. It’s also important that children don’t 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.

What to look for in dewormers for dogs

If you think your dog might have worms, the first step in managing them is a visit to your vet. They will perform an exam and fecal test, which involves looking at a sample of your dog’s stool under a microscope to identify what type of worms they have. Your vet can also assess your dog for other problems that can be caused by a parasite infection.

“I love clients for advocating for their pet and trying, but it’s important to bring your dog into the vet because intestinal parasite infections can often go undiagnosed until more severe symptoms appear like weight loss, diarrhea, and vomiting,” says Dr. Kelley Lay, a Tennessee-based veterinarian, who has worked in a variety of clinic settings over the last decade, including private practice, as a relief veterinarian, and now in nonprofit work.

Lay says over-the-counter (OTC) dewormers are generally not as effective as prescription medicines, and sometimes, an OTC drug might not treat the correct life stages of the parasite. Additionally, if the type of worm your dog has is misidentified, a product might not help at all. Some “worms” are actually single-celled microscopic parasites (protozoa), though they cause many of the same symptoms as intestinal parasites. Things like coccidia and Giardia need to be treated with entirely different medications.

Depending on the type of worms your dog has, effective deworming might require multiple rounds of medication. Your vet will likely want to perform a follow-up fecal exam to be sure all the worms are gone.

Is the product safe and effective? Before giving any deworming medication to your dog, check to make sure it’s approved by the Food and Drug Administration (FDA) or the Environmental Protection Agency (EPA). The FDA’s Center for Veterinary Medicine approves and regulates drugs for animals. For oral products, the searchable Animal Drugs @ FDA database will tell you if a medication is approved. Topical flea and tick products for animals are regulated by the EPA. To confirm that a flea and tick product is EPA-registered, search the EPA’s Pesticide Product and Label System.

Is the product easy to use? Deworming medications for dogs may be given orally as a pill or flavored chew or topically as a solution applied to the skin. Most dogs will eat a flavored chewable tablet or swallow a pill that has been mixed into their food, but if you have the rare dog that rejects pills, a topical dewormer might be easier. When using a topical medication, read the directions carefully to ensure you apply the product properly and follow all precautions. You might need to keep other pets, children, or pregnant people away from treated dogs for a specified period of time.

Is the product legitimate or counterfeit? Counterfeit medications can be ineffective or even harmful to pets and people. Always purchase pet meds from your veterinarian or a trustworthy pharmacy accredited by the National Association of Boards of Pharmacy (NABP) Verified Websites Program, such as Chewy, Petco, and Petsmart. For advice about choosing a reputable pharmacy for pet medication, check out these tips from the American Veterinary Medical Association (AVMA), the FDA, and the EPA. Some red flags include missing directions, foreign-labeled products, and non-English language directions, and packaging that is not child-resistant.

How we selected the best dewormers for dogs

While researching and writing this guide to the best dewormers for dogs, 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,” Smits says. “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 of the best dewormers for dogs 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,” Lay says. 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,” Lay says. 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,” Lay says. “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.”

What are the different 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,” Smits says. “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.