Get

In Your Inbox

Dogster is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

My Puppy Still Has Worms After Deworming: Our Vet Explains

Vet examining puppy

Puppies and worms are like peanut butter and jelly—not that they taste great but rather that they are commonly seen together. Puppies can acquire worms from their mother before they’re even born. They can also acquire them shortly after birth. Worms are so common in young puppies that a vet may forgo a fecal test at your first visit and instead just decide to deworm based on the high likelihood of an infestation.

Fortunately, many dewormers are safe and effective to use on puppies, though you should know what to expect following a deworming. Seeing worms in your puppy’s stool can be normal and doesn’t necessarily mean something went wrong, especially since they’re likely dying worms, not fresh ones. Read on to learn more!

divider dog paws 2 oct 2024

How Do Puppy Dewormers Work?

Dewormers for dogs fall into many different categories based on how they kill the parasites. Some work by paralyzing the worms, causing them to lose their grip on the intestinal wall so they can then be pushed out of the body where they can’t survive.1 Others may block parts of the worms’ metabolic pathways so they can’t produce the energy that they need to survive.

Unfortunately, dewormers only work on adult worms, not larvae or eggs, as there’s nothing to paralyze or metabolically disrupt in these other worm stages. This means dewormers used in puppies only kill the adult worms that are present at the time of deworming. They do nothing to the eggs or larvae in the system or help prevent future infestations.

dog dewormer
Image Credit: Ilike, Shutterstock

Is It Normal to See Worms After Deworming?

Now that you know how these medications get the job done, let’s look into what will be normal to see following a deworming of your puppy. Since most dewormers work by killing the adults or causing them to release from the intestine and get flushed from the system, it is completely normal to see worm bodies in your dog’s feces, especially if they had a heavy worm load. Depending on the dewormer, those worms are dead or will die shortly due to exposure to the environment. You might see worms in your puppy’s stool for a few days following deworming.

Puppies may also vomit worms for a day or two after deworming for similar reasons. The body is just trying to get rid of all the dead and dying parasites. Sometimes, your pup may experience diarrhea as a result of digesting the worm bodies. It should all clear up within a couple of days. If not, consult a veterinarian.

Did you know you can speak to a veterinarian without having to travel? Just head over to PangoVet. It's an online service where you can talk to a vet online and get the advice you need for your pet — all at an affordable price!

PangoVet_Mention-in-Content Savings V1

Does Seeing Worms After Deworming Mean It Didn’t Work?

Besides the expulsion of dead and dying worms, you might see worms in your puppy’s vomit or feces because the dewormer can only kill the adult worms in your puppy’s body, not the larvae or eggs. So, over a bit of time, those other stages can develop into adults, and these may appear during their potty breaks. This is completely normal and doesn’t mean anything went wrong. Your puppy just needs another healthy dose of dewormer.

How Often Should Puppies Be Dewormed?

Deworming often starts with the breeder. Since worms are common in newborn and young puppies, most high-quality breeders will start them on a deworming regime of every 2 weeks. After you bring home the puppy, the veterinarian may continue to deworm them at their vaccination visits, which typically occur every 3–4 weeks, starting at 8 weeks of age.

If your puppy didn’t receive any deworming before they came to you, the vet will likely recommend that they be dewormed at least twice, at 2 weeks apart. From there, fecal samples may be run to determine if further deworming needs to take place.

Older puppies and adult dogs should be dewormed as needed using a fecal test to diagnose worms. Dogs that spend a great deal of time outdoors, especially unsupervised, may need more frequent dewormings.

Reluctant labrador puppy dog getting its worm medication
Image Credit: Ilike, Shutterstock

Do Puppies Really Need Deworming?

While parasites like worms are a natural part of the environment, they’re not something that you want your puppy to live with. Having a few worms usually doesn’t cause a dog much grief, but having a heavy load can be debilitating. Worms siphon nutrients and blood from the puppy, as they often need every bit of nutrition that they can get to grow and develop properly. A large number of worms can cause weight loss, a poor hair coat, and even anemia.

Also, many of the worms that seek housing in our puppies can infest us humans. Hookworms and roundworms are zoonotic, meaning humans can pick them up from canines. Petting your puppy or even letting them lick your face isn’t to blame, though. Rather, humans get infested when they come in contact with larvae or eggs that a puppy expelled into the environment. These parasites can live on grass or in the dirt where your puppy went to the bathroom, and they can infest you if you touch that grass or dirt and accidentally ingest the larvae or eggs. Children are especially at risk, since they tend to put things into their mouths from unwashed hands more readily than adults do.

divider dog paws 2 oct 2024

Conclusion

It can be perfectly normal to see worms in your puppy’s poop following a deworming. This typically means the medication is doing its job of killing the adults and the body is getting them out the best way that it knows how. You shouldn’t be surprised to see worms in your puppy’s poop for up to 2 weeks following a deworming.

That said, seeing worms after a deworming can also mean your puppy is reinfested. The dewormer can only kill adult worms, so after a while, eggs and larvae that were present will have developed into adults. But this just means your puppy needs another dose. Speak to a veterinarian about the best deworming schedule for your puppy to help them stay healthy and worm free.

See also:


Featured Image Credit: D’Action Images, Shutterstock

How useful was this post?

Click on a star to rate (you can leave written feedback after clicking submit)

Help us improve Dogster for pet parents!

Your feedback really matters.

What did you like about this post? Also how can we improve it?

Join the conversation

2 Responses

    1. Hi Yvonne,

      Thanks for reaching out to us, we’d love to help. It's difficult to say with certainty, though in some instances the passing of dead worms for a time after deworming can be normal. We do have an online vet service, PangoVet (https://pangovet.com) where you can book a consult and have a face-to-face virtual chat with one of our experienced vets and they can help answer any questions you have and let you know if there’s anything more you should be concerned about.

Leave a Reply

You’re very welcome to leave a comment or question. Please know that all comments must meet our community guidelines, and your email address will NOT be published. Let’s have a positive and constructive conversation.

Talk With A Vet Online

Peace of mind,
anywhere, anytime

Affordable vet advice

Are Dogs Allowed in Lowes? (Updated in 2025)

Lowes is a well-known retailer with a vast inventory of tools, equipment, lumber, hardware supplies, and plants. If you are a frequent shopper,...

Brachycephalic Dogs & Heat: Vet-Explained Concerns

With summer fast approaching and temperatures on the rise, it’s a good time to think about warm weather safety. As many owners have...

150+ Australian Shepherd Names: Interesting & Popular Ideas

Your dog’s name is one of the most important words that they will ever learn. We humans develop attachments to our names early...

18 Goldendoodle Colors & Patterns (With Pictures)

The Goldendoodle is one of the most popular hybrid dogs, and it’s no wonder. When you combine the loving and social Golden Retriever...

More related

My Dog Ate a Silica Packet: What to Do (Vet Answer)

There are things in our environment that can pose safety risks to our pets that we don’t always consider until ingestion occurs by...

Ask Dr. Paola- Eating Grass, Anti-Aging Pills & Heartworm (June 2, 2025)

Welcome to our “Ask Dr. Paola” series, where every Monday we bring expert advice straight from Dr. Paola Cuevas (MVZ) to help our...

7 Best Dog Foods for Pitbulls to Gain Muscle in 2025 – Reviews & Top Picks

As pet owners, we all want our companions to thrive and give them the best we can give them when it comes to...

10 Best Large Dog Nail Clippers in 2025 — Reviews & Top Picks

As a dog owner, you probably know that clipping your dog’s nails is a part of the grooming process. However, choosing the right...

Keep reading

11 Best Foods for a Corgi Puppy in 2025 – Reviews & Top Picks

Congratulations on your new Corgi puppy! These affectionate, medium-sized dogs are an excellent addition to any household. You want the best for your corgi, starting with the right puppy food. If you’re overwhelmed by all of the pet food brands...

Hungry Welsh corgi Pembroke or cardigan puppy eats from ceramic bowl standing on fleecy carpet

Is Dry Dog Food Bad for Dogs? Vet-Reviewed Pros & Cons

There has been controversy surrounding dry food in the dog food world for years now. Proponents of raw food and fresh food diets argue that dry dog food is unhealthy due to being highly processed, but others have a more...

pouring dog food

6 Homemade Dog Cake Recipes: Vet-Approved Nutritious Options

Ready to celebrate your dog? These six delicious dog cake recipes will show the world that you love your dog to the moon and back. The best part is that they’re human-grade, which means you can have a slice as...

Freshly baked carrot cupcakes on a plate

Can Dogs Eat Eggs With Cheese? Vet-Reviewed Health & Nutrition Guide

Feeding your dog tasty treats is one of the simple joys in life, and as many dog owners will attest, it’s even more fun when you and your pet can share the same meal. If you’ve just made a delicious...

Can Dogs Eat Eggs With Cheese

10 Best Dog Foods for Morkies in 2025 – Reviews & Top Picks

Morkies are tiny, but that doesn’t mean they don’t have an appetite! These little dogs are surprisingly high-energy. That set of traits comes with its own challenges when you need to pick a food. Finding a food that will pack...

Morkie lying in bed_SarahChai_Pexels

Are Tomato Plants Toxic to Dogs? Vet-Verified Facts & Safety

If you get online regarding feeding dogs tomatoes, you’ll get mixed opinions. Some say that you should never give your dog any tomatoes, despite their ripeness, while others claim that ripe tomatoes can be okay in moderation. Ultimately, you should...

Dogster_Are Tomato Plants Toxic to Dogs

Can Dogs Eat Kumquats? Vet-Reviewed Facts & FAQ

A kumquat is a small citrus fruit native to Southeast Asia that looks similar to an orange. They aren’t nearly as common as mandarin oranges but can still be found in kitchens around the world. Before you share your snack...

Can Dogs Eat Kumquats

10 Best Puppy Foods for Small Breeds in 2025 – Reviews & Top Picks

Small dogs may think they are big and intimidating, but their nutritional needs are unique. Small breeds have smaller stomachs and higher metabolisms, so they need nutrient-dense formulas to ensure adequate nutrition without weight gain. Finding the appropriate food for...

jack russell terier puppy eating food from bowl