Worms in Dogs: Treating Your Dogs Intestinal Parasites

10 Minute Read
Updated July 16, 2021

Have you noticed your dog doing that tell-tale butt scoot across your living room carpet? Or maybe you found something squirming in his poop. If so, your dog has worms. Yuck!

Worms are not uncommon in dogs. They have a proclivity for eating gross things that they find on the ground, in the garbage, or even “waste” from wild animals. This leaves plenty of chances for opportunistic parasites to sneak into your dog’s gut. 

Worms can be a nuisance and can cause some pretty unpleasant problems, but worms in dogs are easier to treat and prevent than you might think. In this article, we’ll help you learn to identify symptoms of worms in dogs, effectively treat them, and most importantly, prevent worms from coming back. 

Types of Worms in Dogs

There are several types of worms that can infect your dog’s body, but the most common types you’ll see in your dog’s gut are roundworms and hookworms.

Worms are especially common in puppies and strays, due to their lack of personal hygiene, but any dog can get worms at any life stage if they come in contact with contaminated debris.

Here are some of the most common worms to be on the lookout for in dogs:


Roundworms are the most common worms found in pets. These worms are ingested by your dog, usually as eggs, through contaminated soil, animal feces, or from ingesting infected wild animals. Additionally, roundworms can be passed from mother to puppy in the womb or through their milk. 

Once ingested, roundworms feed on partially digested food in your dog’s digestive tract and complete their lifecycle. The lifecycle of roundworms is complicated but effective. Like most pests, they have three stages: eggs, larvae, and adults. 

Eggs are ingested by your dog, and they hatch into infective larvae within 2-4 weeks. From there they work their way through the intestinal wall and into the liver, then onto the lungs. Once they reach the lungs, the larvae can either work their way to your dog’s trachea and are swallowed. Once back in the intestines, they mature to adults, lay eggs, and start the cycle over again. 


This aptly named parasite is shaped like a hook about the size of a penny and has multiple sets of teeth that allow them to latch onto the walls of your dog’s small intestine to feed on your dog’s blood.

The life cycle of hookworms is similar to roundworms, but typically a little faster, as the larvae can reach their infectious stage in about a week. The biggest difference between these two common intestinal parasites, besides their food source, is that hookworms can also penetrate the skin to infect your pet. Eeek!


Whipworms, though less common, is another type of intestinal parasite that can be found in dogs. They are ingested as eggs and develop in the intestinal tract like other worms, but these guys don’t travel outside of the intestines as round and hookworms do. 

Additionally, hookworms have a longer developmental period, about 3 months, whipworms are usually not diagnosed in young puppies under 6 months of age. 

All three intestinal worms above are shed in egg form, in your dog’s feces, which means soil contamination is common in places where dogs or other animals deposit their waste. Dog parks, fields, and even your backyard could be the most likely environment for round, hook, and whipworms to spread. 


Another type of worm that can infect your dogs is tapeworms. Unlike other intestinal worms, tapeworms can’t just be ingested to infect your dog. They are passed through a third-party pest, like dog fleas or mites. 

Tapeworms are also different in that they have self-sufficient segmented bodies, each being able to survive and reproduce on their own. As the tapeworm grows, the mature segments of the worm are gradually shed, making their way to your dog’s feces. 

Tapeworms get much bigger than other types of intestinal worms. They can grow from 4 up to 28 inches in length, though the parasite is usually treated well before it gets to this size. 


Lab-covered-in-mosquitos (1)

The most deadly worm on our list is heartworm. These parasites attach both your dog’s heart and lungs, reproducing and growing until permanent damage is done to the organ. Heartworm, like tapeworm, is spread through an intermediary pest, in this case, mosquitoes, but instead of being ingested with the pest, the larvae travel through your dog’s bloodstream.

Untreated, heartworm is fatal, so if you live in an area of high risk, like Ontario, talk to your vet about different options for preventing heartworm infestations. 

Parasites in Dogs

All worms are parasites, but not all parasites are worms. Some parasites in dogs are much smaller but can also be much more of a nuisance. Single-celled parasites can quietly invade your dog’s systems and lead to some unpleasant consequences. 

These parasites are easily spread through water and soil that have been contaminated by fecal matter. The most common places for these parasites to thrive are in parks, ponds, and forests where wild animals or other dogs make a… uh… deposit.

The most common parasites that can affect dogs are coccidia and giardia. Both parasites typically cause diarrhea and other digestive issues.

Parasites are particularly dangerous for puppies and older or immune-compromised as they can’t fight infection as effectively. 

Signs of Worms in Dogs

How can you tell if your dog has worms? Unfortunately, worms aren’t the easiest things to diagnose at home. Signs of worms are often subtle at first, but if you know what to look for, then you can treat the worms before they cause too much discomfort. 

Unlike other pests that leave visible signs of activity on your dog’s skin, worms burrow in your dog’s digestive tract or other organs, so you can’t see them unless they make their way out of your dog’s body. This means they are going to make their way out of one end, or the other…

Let’s take a look at how you can see if your dog has worms:

Worms in Dog Poop

The number one way of identifying worms in your dog is through their stool. Depending on the type of worm, you may see small worms present in your dog’s poop. This doesn’t happen for every type of worm though. 

Roundworms can sometimes be found in stool, and tapeworms shed fully autonomous segments of the body as they grow. Tapeworm segments in dog poop typically look like grains of rice, while roundworms are a little larger.

Note that for many types of worms, you won’t see that evidence in their stool, so don’t count on this as the only method of diagnosing your pet. 

Worm Eggs in Dog Poop

Most worms release their eggs into the digestive tract and they will end up in your dog’s poop. Don’t count on spotting them though, the eggs are too small, but they can be seen under a microscope. This means you can bring a stool sample to the vet to confirm a worm diagnosis. 

Worms in Dog Vomit

Another way to see visible signs of worm activity in your dog is in their vomit. Many varieties of worms travel through your dog’s bloodstream during their larval stage and make their way to your dog’s trachea so they can be swallowed to finish their life cycle. 

This often ends in the worms being either coughed up or puked up. Worms in dog vomit may be extremely unpleasant, but at least you can confirm your diagnosis and begin treatment immediately. 

Symptoms of Worms in Dogs

lethargic-sick-dog (1)

Physically seeing the worms infesting your dog is only one way of diagnosing your dog. Dogs with worms can show health symptoms as a result of their squirmy intruders. Though early worm infestations often don’t have symptoms, there are some symptoms you can keep an eye out for. 

    • Bloating
    • Diahrrea
    • Vomiting
    • Coughing/Hacking
    • Bloody in Stool
    • Anemia
    • Lethargy
    • Butt Scooting

Butt scooting is the symptom most commonly thought to be a tell-tale sign of worms, but that’s actually not true. Worms can cause irritation that leads to butt scooting, but it’s far from the most common symptom. 

More often than not, butt scooting is a sign of an anal gland issue, not worms. Talk to your vet about your dog’s anal gland health. 

Deworming a Dogs

What does deworming a dog mean? It’s pretty straightforward - to get rid of worms, but a good dewormer has to get rid of worms at all life stages. Larvae and adults are easily susceptible to deworming medications, but the eggs will survive. 

This is why deworming treatments often need to be administered twice to allow eggs to hatch before the second treatment. Talk to your vet about the best deworming options for your dog, or check out some of these natural deworming options. 

Natural Dewormers for Dogs

Some of the most effective ways to kill worms are also some of the harshest options for your dog. While dewormers are generally considered safe, some of you may be looking for more natural options to treat your dog’s squirmy intruders. 

Like most supplements, natural alternatives are typically effective for most dogs, but that doesn’t mean they are guaranteed to work for every dog. Additionally, natural options often don’t work as quickly, especially if you don’t follow the recommended instructions, or continue the treatment for long enough, you may find the worms make an unpleasant comeback. 

Diatomaceous Earth for Parasites in Dogs


Well known for its pest control properties, diatomaceous earth works best internally. The small, sharp particles are harmless for your pooch but are small enough to pierce the worms, causing them to dehydrate and die off. 

It’s not the fastest method of deworming your dog, but it is one of the safest. Like most dewormers, the treatment should be done twice, with a seven-day break in between to allow eggs to hatch. 

This is one of the most popular preventative dewormers, as it can be done often throughout the year without any negative effects. 

Learn more about how you can use Diatomaceous Earth to keep your pet pest-free in What is Diatomaceous Earth for Dogs.

Coconut Oil for Worms in Dogs


Coconut oil contains lauric acid, which is a natural anti-parasitic. Feeding coconut oil regularly can be a useful preventative for many types of worms and other parasites including giardia. 

While coconut oil does have its benefits, too much of a good thing can still be bad. Coconut oil is high in calories, so you should always feed coconut oil responsibility. The standard recommendation is about ½ tsp of coconut oil per 10 lbs of body weight. 

Learn more about the pros and cons of coconut oil in  Benefits of Coconut Oil for Dogs.  

Side Effects of Deworming a Dog

Some dewormers can cause some temporary side effects. Some dogs are lucky and have no issues, while others can have some minor digestive issues as a result of the deworming process. 

Effects are typically short-lived and mild. They should clear up on their own by the time the treatment is completed. If the side effects last longer than a week, you should speak with your vet. 

Preventing Worms in Dogs


Like with most pet health issues, prevention is always the best medicine. Regular deworming can prevent worms from populating and causing issues for your pet before they start. 

Worms can be anywhere in your dog’s environment, and you can’t always ignore them. That doesn’t mean you shouldn’t try though. 

Worms and other parasites spread through fecal matter, so if your dog loves to sniff out poop from wild animals or even himself, then he’s likely exposed to worm eggs and larvae quite frequently. 

Be aware of the “things” your dog finds on your walks and trips to the dog park as well as the wild animals they can come in contact with. This is also another reason to keep your yard free of poop and other debris.

Additionally, worms that are spread through fleas or mosquitos can be avoided if you use appropriate flea medications like Bayer Advantix ii so make your dog an unpleasant environment for pests to latch onto. 

How Often Do You Have to Deworm a Dog

Preventatively deworming your dog is a good way to keep worms away, but how often do you have to deworm your dog. This will depend on the type of dewormer you use and how frequently your dog is exposed to worms. 

Monthly deworming treatments are recommended for warmer seasons when your dog will spend the most amount of time outdoors and will have the most exposure to worm eggs. During colder months, or dogs that have more controlled environments can be dewormed four times per year. 

Dewormers won’t hurt your dog if they don’t have worms, which is why using a dewormer preventatively is a common practice.

Worms Happen

The idea of worms crawling around in your dog’s system is pretty unpleasant to consider, and the longer the worms are allowed to thrive, the more damage they can do. If you aren’t sure, talk to your vet. Your vet can take stool samples and confirm the worm diagnosis and help you choose the most effective treatment for your unique dog. 

Worms are probably going to happen at some point in your pet’s life. The fact is your dog has ample opportunity to catch a case of worms, even in his own backyard. You can’t keep your dog inside forever, so accept the fact that worms happen and learn how to identify and treat them properly. 

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How do you protect your dog from worms? Share your tips and success stories with us in the comments below!

Written by

Krystn Janisse

Krystn is a passionate pet nutrition enthusiast. She has worked in the pet industry for over a decade and loves to share her passion for animal welfare with others. She loves all animals but is currently channeling some crazy cat lady vibes with her four lovable, but rebellious cats.


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