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Whipworms in Dogs

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Life with a dog means most days are filled with simple delights like long walks, fetch, and cuddles, so when your pet starts acting not quite like herself, you notice. If your dog seems low on energy or has recently started making a mess in the house, she might have a whipworm infection. 

The good news: Despite their intimidating name and eerie, thread-like appearance, whipworms are a common, easily treatable parasite in dogs. In fact, research shows cases of whipworm have gone down from 2012-2018, possibly in part due to the use of preventive medication, finds a recent study in Parasites & Vectors (1). Unfortunately, despite this drop in prevalence, whipworm is still one of the most common intestinal worms found in dogs. 

If you’re wondering what’s wrong with your dog (and suspect whipworms might be the culprit), treatment is just one veterinary appointment away. In fact, some monthly heartworm preventives actually treat whipworms with each dose too, in addition to preventing heartworm disease.

Here, learn everything you need to know about whipworms in dogs and how to protect your dog from them.

What Are Whipworms in Dogs?


Along with tapeworms, hookworms, and roundworms, whipworms are one of the most common intestinal parasites found in dogs. Named for their shape, these parasites have a thin front end (the “lash” of the whip) and thick posterior end (the “handle” of the whip). Adult worms are 4.5 to 7.5 centimeters long (2).

Small yet formidable in large numbers, whipworms can seriously impact your dog’s health when they latch onto the lining of her cecum and large intestine. 

Over time, the irritation caused by whipworms feeding on your dog’s intestines can lead to some worrisome symptoms like bloody diarrhea and weight loss.

How Do Dogs Get Whipworms?

dog sniffs in garden

Dogs of all ages can pick up whipworms when they play in or eat infected soil, dirt, or poop (hello, dog park!). When a dog contracts whipworms, adult whipworms lay eggs inside her intestines, which are then passed in her poop. (The eggs are so tiny though, you can’t see them.) Within about nine to 21 days, the eggs mature and whipworms can then re-infect her and other dogs (2). 

Whipworm eggs are very hardy and can stick around in the environment for years. So if your dog has a whipworm infection, he can easily get re-infected from eggs that were previously passed into the environment.

While whipworm infections often recur in dogs, there’s no need to worry about contracting whipworms yourself. The type of whipworms that infect dogs don’t pose a threat to humans, so your dog can’t pass them on to you, says Dr. Amy Stone, a clinical assistant professor and chief of the primary care and dentistry service at the University of Florida College of Veterinary Medicine

That being said, as a best practice, you should always stick to good poop-scooping hygiene and wash your hands immediately afterward. 

Whipworm Symptoms in Dogs 

If your dog has whipworm, she might become dehydrated and weak, lose weight, or have bloody diarrhea, all a result of feeding whipworms, says Stone (we know—ugh!). 

As you can imagine, your dog’s quality of life goes down in general when she has a whipworm infection, and the more the infection progresses, the more symptoms will emerge. Your dog might also have trouble controlling her bowels, strain to go to the bathroom, or develop anemia (which causes pale gums). Dogs with whipworm infections can have big bellies and look scruffy and unthrifty. If left untreated, whipworm in dogs can lead to serious disease. 

While there are certain signs of whipworm in dogs to look out for, some dogs can have a whipworm infection and show no symptoms whatsoever, which is why regular check-ups and monthly medication that protects against whipworm are so important. 

Keep in mind that whipworm infections can be especially harmful for puppies, dogs with weakened immune systems, and seniors. Furthermore, the signs of whipworm in dogs often overlap with those of other parasites and serious health conditions, so if you think your dog might be sick, call your veterinarian for help. 

Diagnosis of Whipworm in Dogs

whipworm eggs under microscope

Your veterinarian can diagnose whipworm by examining your dog’s poop for whipworm eggs. This is called a fecal flotation test, as your veterinarian can see eggs rise to the surface of a prepared slide underneath a microscope. Because whipworm and other parasites are so common in dogs, most veterinary clinics require this test every six to 12 months for all dogs, says Stone. 

However, since whipworm eggs can take a while to appear in your dog’s poop after an infection, the test may result in a false negative. Whipworm eggs are also very heavy, so they may not rise to the surface during the test. In these situations, your veterinarian can still diagnose a likely case based on common signs of whipworms in dogs, namely chronic diarrhea and weight loss. 

Given the challenges surrounding whipworm diagnosis—not to mention the unpleasant symptoms—it’s best to consider your monthly treatment options.

Whipworm Treatment in Dogs

While a whipworm infection can be scary, thankfully, treatment is easy. If your dog has a whipworm infection, your veterinarian will prescribe a dewormer to kill the worms and give her some much-needed relief. After your dog’s initial prescription, your veterinarian may recommend repeat treatments to control the infection. 

Do not be alarmed if you see worms in your dog’s stool after deworming. It is common for dogs to pass worms post-treatment—it’s normal and means the product is working.

Some monthly heartworm preventive medications also deworm monthly for additional parasites, including whipworm. These products can be used to both treat your dog’s whipworm infection as well as protect her against future infections.

Whipworm Medicine for Dogs 

Some common deworming medications like milbemycin oxime and fenbendazole are commonly prescribed whipworm treatments, says Stone. Since some monthly broad-spectrum parasite protection medications like Interceptor® Plus (milbemycin oxime/praziquantel) also treat whipworms (among other common parasites like hookworms, roundworms, and tapeworms), this is a simple way you can make sure your dog is protected long-term. To protect against reinfection, make sure every dog in your household is treated regularly.

See important safety information for Interceptor® Plus below.

Cost to Treat Whipworms in Dogs 

The cost of whipworm treatment will vary, depending on whether you are using just a whipworm dewormer or if you are using broad-spectrum heartworm prevention, but is fairly affordable. You may find it more cost effective to use a monthly heartworm preventive that includes whipworm coverage. If your dog is on the larger side, keep in mind that the price might be higher.

Whipworm Disease Prevention in Dogs

As re-infection with whipworm is a common occurrence, don’t get discouraged if it takes a while for your dog’s infection to clear up. While she’s recovering, you can help lower her chances of becoming re-infected with a few simple steps. 

Make sure your yard is free of dog poop and that new poop is bagged or scooped immediately to prevent more whipworms from entering the environment. Don’t forget that infective whipworm eggs can persist in your yard for many years, so your dog is still at risk for infection even if you diligently clean up after her.

Regularly check her poop for signs of worms (think: bloody and watery), and keep her on a monthly medication that protects against whipworm, says Stone. In addition to a deworming medication like Interceptor Plus, consider a broad-spectrum program that targets other parasites like ticks and fleas—both of which Credelio® (lotilaner) covers.

If your dog seems like she might be sick, remember: symptoms of whipworm and other conditions can sometimes be subtle or take time to emerge. To be safe, check in with your veterinarian. Then, after your dog has been properly diagnosed and treated, you can get back to enjoying quality time together. 

Credelio Indications

Credelio kills adult fleas and is indicated for the treatment and prevention of flea infestations, treatment and control of tick infestations (lone star tick, American dog tick, black-legged tick, and brown dog tick) for one month in dogs and puppies 8 weeks and older and 4.4 pounds or greater.

Credelio Important Safety Information

Lotilaner is a member of the isoxazoline class of drugs.  This class has been associated with neurologic adverse reactions including tremors, incoordination, and seizures. Seizures have been reported in dogs receiving this class of drugs, even in dogs without a history of seizures. Use with caution in dogs with a history of seizures or neurologic disorders. The safe use of Credelio in breeding, pregnant or lactating dogs has not been evaluated. The most frequently reported adverse reactions are weight loss, elevated blood urea nitrogen, increased urination, and diarrhea.  For complete safety information, please see Credelio product label or ask your veterinarian.

Interceptor Plus Indications

Interceptor Plus prevents heartworm disease and treats and controls adult roundworm, hookworm, whipworm, and tapeworm infections in dogs and puppies 6 weeks or older and 2 pounds or greater.

Interceptor Plus Important Safety Information

Treatment with fewer than 6 monthly doses after the last exposure to mosquitoes may not provide complete heartworm prevention. Prior to administration of Interceptor Plus, dogs should be tested for existing heartworm infections. The safety of Interceptor Plus has not been evaluated in dogs used for breeding or in lactating females. The following adverse reactions have been reported in dogs after administration of milbemycin oxime or praziquantel: vomiting, diarrhea, decreased activity, incoordination, weight loss, convulsions, weakness, and salivation. For complete safety information, please see Interceptor Plus product label or ask your veterinarian.

Disclaimer: The author received compensation from Elanco US Inc., the maker of Interceptor Plus and Credelio, for her services in writing this article. 


  1. Drake, J., Carey, T. Seasonality and changing prevalence of common canine gastrointestinal nematodes in the USA. Parasites Vectors 12, 430 (2019) doi:10.1186/s13071-019-3701-7
  2. Trichuris Vulpis for Dogs. Companion Animal Parasite Council. Retrieved from https://capcvet.org/guidelines/trichuris-vulpis/

Credelio and Interceptor are trademarks of Elanco or its affiliates. 

© 2020 Elanco.  PM-US-19-2131

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