While unpleasant to think about, the reality is that worms are quite common in dogs. In a recent study, intestinal parasites like hookworms and whipworms were found in more than 20 percent of dogs and 85 percent of dog parks across the United States (1). 

The good news is that it’s easy to treat worms in dogs and protect your canine companion against future infections. There are several dewormers for dogs available on the market that can be used to get rid of worms. There are also long-term parasite control products that are effective against multiple types of worms and can be used year-round. 

Here’s a sneak peek at the top vet-approved dog dewormers that made our list.

All featured products are chosen at the discretion of the Great Pet Care editorial team and do not reflect a direct endorsement by the author.

Our Top Picks

• Best with Flea and Tick Protection: NexGard Plus
• Best with 5-Worm Protection: Interceptor Plus  
• Best with Flea Control: Trifexis  
• Best Broad-Spectrum: Drontal Plus
• Best with Heartworm Prevention: Heartgard Plus

Now, let’s take a closer look at why deworming dogs is so important, plus explore some of the top dewormers for dogs.

What Is Deworming for Dogs?

All dogs are at risk for encountering worms, such as hookworms, roundworms, whipworms, and tapeworms. Dewormers are medications that kill intestinal parasites that your dog may have contracted. “Broadly, these medications are called anthelmintics,” explains Dr. Audrey Wystrach, DVM, CEO of Petfolk. Some medications also help to prevent reinfection for a period of time. 

“Many deworming products are effective for more than one type of worm,” Dr. Wystrach adds. “There are many different varieties and drug classes; generally, products that are effective against flat-shaped worms like tapeworms are not effective against round-shaped worms, such as roundworms, whipworms, and hookworms.” 

Dewormers are available in a variety of forms, such as pills, chewable tablets, and liquids. Some of the common active ingredients you’ll see in dewormers for dogs include:

• Febantel or Fenbendazole : Used to treat roundworms, hookworms, lungworms, whipworms, and some rare species of tapeworms
• Ivermectin: Heartworm preventative that’s also effective against hookworms and roundworms
• Pyrantel Pamoate: Effective against intestinal roundworms and hookworms
• Praziquantel: Most commonly used to treat tapeworms

Wystrach notes that while most dewormers for dogs need to be prescribed by a veterinarian, there are some over-the-counter options available. 

How Do Dogs Get Worms?

You might not think your dog has worms, but unfortunately, your pup can pick up these parasites just from being outside. From sticking their nose in the dirt at the dog park to chasing and eating small animals, there are many scenarios that can put dogs at risk of contracting worms. 

“Intestinal worms, such as hookworms, roundworms and whipworms, are commonly transmitted when dogs ingest contaminated soil or feces containing eggs, or immature worms that have been passed from other infected animals in the environment,” explains Dr. Wystrach. 

Your dog can also become infected with a common species of tapeworm by accidentally ingesting an infected flea while grooming themselves. 

Another type of worm that dogs are at risk of, though it’s not an intestinal worm, is called a heartworm. Heartworm is an internal parasite that lives in the blood vessels inside the lungs and heart. Dogs can get heartworms after being bit by an infected mosquito. Heartworms can cause organ damage, heart failure, and death if left untreated. 

Why Dewormer for Dogs Is Important

Dewormer for dogs is not only important to rid your pet of an infection but also to keep the entire household healthy. Some intestinal worms, like roundworms and hookworms, are also infectious to people.

If left untreated, these parasites can cause serious health problems for your dog. Intestinal worms can lead to a variety of gastrointestinal symptoms, such as diarrhea, abdominal pain, weight loss, and vomiting. As such, most veterinarians recommend using year-round parasite protection to keep your dog healthy and avoid reinfection. 

If your dog has intestinal worms, your veterinarian will prescribe a deworming medication. Once the infection has cleared, your veterinarian may recommend year-round parasite protection medication. In other cases, your veterinarian may just recommend treating the infection with a long-term parasite protection medication and keeping your dog on it year-round. In other words, year-round parasite protection medications are dewormers. 

If your dog is on a heartworm preventative, know that these are often effective against some intestinal worms, too.

5 Vet-Approved Dewormers for Dogs

All featured products are chosen at the discretion of the Great Pet Care editorial team and do not reflect a direct endorsement by the author.

It’s important to talk with your veterinarian to choose the best dewormer for your dog. “Product type, dosing, and frequency are all very important factors when considering treatment,” explains Dr. Wystrach. Your veterinarian will also consider factors such as your dog’s age, breed, and other medical conditions to select the best option for the treatment and/or control of worms.

Best Dewormer for Dogs with Flea and Tick Protection

Our pick: NexGard Plus

Roundworms and hookworms are two of the most common intestinal worms in dogs, and they are also infectious to people. NexGard PLUS treats and controls three species of hookworms and two species of roundworms in dogs. The active ingredients are afoxolaner, moxidectin and pyrantel. These monthly, beef-flavored chews also kill fleas and ticks and prevent heartworm disease.

See important safety information for NexGard PLUS below.

Highlights

• Beef-flavored soft chew is easy to give once a month
• Treats and controls roundworms and hookworms
• Also protects dogs from fleas and ticks and prevents heartworm disease
• Approved for puppies as young as 8 weeks weighing 4 pounds or more

Things to Consider

• Does not protect against whipworms or tapeworms; however, it does kill fleas, which can carry tapeworms
• Available by prescription only
• Dogs should be tested for existing heartworm infection prior to starting this product

Best Dewormer for Dogs with 5-Worm Protection

Our Pick: Interceptor Plus 

Interceptor Plus is a monthly, chicken-flavored chewable that covers five types of dangerous worms. It protects dogs against heartworm disease and hookworm, roundworm, tapeworm, and whipworm infections. The active ingredients in Interceptor Plus are milbemycin oxime and praziquantel. This prescription medication is suitable for dogs 6 weeks or older and 2 pounds or greater.

Highlights:

• Prevents heartworm disease
• Treats and controls roundworm, hookworm, whipworm, and tapeworm infections
• Given once monthly
• Chicken-flavored chewable tablets

Things to Consider

• Available by prescription only

Best Dewormer with Flea Control

Our pick: Trifexis 

Because fleas can carry a common species of tapeworm, you may want a product that offers flea control in addition to deworming. Trifexis is a comprehensive option in this regard—it not only deworms but also offers heartworm prevention and kills adult fleas. The prescription medication is effective against hookworm, roundworm, and whipworm infections, and it comes in small, beef-flavored tablets. It can be given to dogs 8 weeks and older, and it’s designed to be used on a monthly basis.  

Highlights

• Prevents heartworm disease
• Treats and controls hookworm, roundworm, and whipworm infections
• Kills adult fleas and prevents flea infestations
• Beef-flavored tablet

Things to Consider

• Available by prescription only
• Does not treat and control tapeworm infections. However, it kills fleas, which can carry tapeworm
• More expensive than other dewormers

Best Broad Spectrum Dewormer for Dogs

Our pick: Drontal Plus

For a dewormer that’s effective on a wide range of parasites, Dr. Wystrach’s top choice is Drontal Plus. “We recommend Drontal Broad Spectrum Dewormer because it is safe, effective, and eliminates all parasites within seven days,” says Dr. Wystrach. This prescription medication treats tapeworms, hookworms, roundworms, and whipworms using a combination of praziquantel, pyrantel pamoate, and febantel. This dewormer comes in both tablet or chewable forms, and it can be given to dogs over 3 weeks old. 

Highlights

• Kills nine species of intestinal worms
• Available in tablet or chewable form
• Suitable for dogs and puppies over 3 weeks old
• FDA-approved
• Affordable

Things to Consider

• Available by prescription only

Best Dewormer with Heartworm Prevention

Our pick: Heartgard Plus

Many pet owners like to take care of regular deworming and heartworm prevention in one step, which is why Heartgard is so popular. When given on a monthly basis, the prescription medication uses ivermectin to kill heartworm larvae, and it also treats several types of hookworms and roundworms. Heartgard tablets have a chewable beef-flavored form, and the medication can be given to puppies starting at 6 weeks old. 

Highlights

• Provides heartworm prevention
• Kills hookworms and roundworms
• Beef-flavored chewable tablets
• Suitable for dogs and puppies over 6 weeks old

Things to Consider

• Available by prescription only
• Certain dog breeds are sensitive to ivermectin
• Doesn’t treat or control whipworms or tapeworms

Buyer’s Guide: Dewormer for Dogs

Here are some factors to take into consideration before choosing a dewormer for dogs:

Proper diagnosis: If you think your dog has worms, it’s essential to bring your dog to the veterinarian to get a proper diagnosis before treatment. “Parasitism is an important conversation to have with your veterinarian,” Dr. Wystrach says. “A fecal evaluation is critical to define and diagnose the type of parasitism present, as well as the proper treatment protocols and safety precautions. It is important to note that, many times, pets harbor more than one parasitic infection at a time.”

Types of parasites: There are several types of intestinal worms that can affect dogs. Different medications are effective against different parasites, such as tapeworms, hookworms, roundworms, and whipworms. Some dewormers also help to prevent heartworm disease, which can cause serious illness and death. 

Active ingredients: Some of the most common active ingredients in dog dewormers include febantel, ivermectin, pyrantel pamoate, and praziquantel. Each one is effective against specific types of worms. Talk to your veterinarian about which ingredients make sense for your pet.

Frequency and dosing: When selecting a dewormer, you’ll also want to consider how often it needs to be administered and the proper dose for your pet. Medications that contain a heartworm preventative are typically given on a monthly basis.

Parasite prevention: Even if your dog doesn’t currently have worms, your veterinarian may recommend a year-round parasite protection product based on your pet’s individual needs and offer guidance on the proper dosage and frequency.

Dog Dewormer FAQs

How often should you deworm your dog?

The Companion Animal Parasite Council recommends that all dogs be on year-round parasite prevention that protects against both heartworms and intestinal worms. If you do not give monthly heartworm prevention to your dog, you should administer a dewormer at least once every three months. 

How long does it take for a dog dewormer to work?

Dog dewormer starts working quickly, usually within a few hours of administering the product. However, it may take up to a week to completely rid your dog of parasites.

Does dewormer cause diarrhea in dogs?

Side effects after deworming are relatively uncommon. When they do occur, side effects include lack of appetite, gastrointestinal upset, vomiting, and diarrhea. You may notice visible worms passing in your dog’s stool, as the worms die and leave the intestines.

Is there such a thing as a natural dewormer for dogs?

If you believe your dog has worms, Dr. Wystrach advises against using a natural dewormer. “Many naturally occurring plants and remedies can be toxic or harmful to pets,” she says. “Natural does not equate to safe.”

NexGard PLUS Important Safety Information

NexGard® PLUS (afoxolaner, moxidectin, and pyrantel chewable tablets) is safe for puppies at 8 weeks, weighing 4 pounds or more. The most frequently reported adverse reactions include diarrhea, vomiting, lethargy, and itching. Use with caution in dogs with a history of seizures or neurologic disorders. Dogs should be tested for existing heartworm infection prior to starting a preventive. For more information, click here for full prescribing information.