Are Puppies Born with Worms? (Just How Common Are They)

are puppies born with worms

If your dog has just had puppies, or perhaps you are picking up a puppy for the first time, then worms could be a concern. In this short guide I will answer the questions you might have about puppies being born with worms, and how common this is. I’ve also included some deworming tips, should you need them.

Are puppies born with worms? Most puppies are naturally born with worms or can contract worms through drinking their mother’s milk. There is no available data to say what percentage of puppies are born with worms, but vets say almost all puppies are always born with worms.

How common are worms in puppies?

The short answer is that it’s very common for puppies to have worms. How many puppies are born with worms is hard to say, but many vets say it’s more common than not.

Most puppies can be born with worms, as parasites will be passed down in utero from their mother or they can even contract worms from drinking their mother’s milk after being born.

how common are worms in puppies
Puppies can carry worms from a young age, even just after being born. It’s very common.

The dormant eggs of by-gone parasites can lay dormant in the mother which can be awakened by pregnancy. Generally, it is not recommended to deworm a pregnant dog, puppie are almost always going to be born with worms.

Puppies can also contract worms by:

Handy Hint: Puppies can also be born and quickly get fleas. Here’s advice I’ve written about treating newborn puppies who get a flea infestation.

How do you know if your puppy has worms?

There are some clear ways to tell if your puppy has worms. Here are some signs to look for to check if your puppy has been infected with parasites. The most common symptoms are:

But and this is a big but, deworming your puppy is what a responsible puppy owner does. Just like going for walks, playing and training, worming your puppy is part of the course that you should be expecting to do as soon as you welcome a puppy into your life.

Worms in puppies are so common that you should just assume they have them and treat them regularly.

When should puppies be dewormed?

Most vets recommend that your puppy begin de-worming medication after 2 to 3 weeks of them being born. You can read a full schedule here.

Given that most people get a puppy home from 8 weeks and up, you are perfectly fine to start them on worming treatment. Please consult with your vet to find out what deworming treatment they recommend for a puppy at various ages.

Handy Hint: Here’s what the right age to sell a puppy is according to the law and ethical considerations.

What types of worms can puppies get?

It’s not just one type of worm you have to worry about. Puppies can get various types of worms, include the following nasties.


Roundworms are the most common, specifically one called toxascaris leonina. However, the toxocara canis is the nastiest parasite you need to be the most worried about. This is the strain often contracted by puppies, and it can also be passed from puppies to humans if you are not careful.

Don’t act surprised, dear reader! We have all seen puppies eat their own poop and yet somehow forget later in the day and let them lick you on the mouth.

Pets and Parasites writes,

“Humans can accidentally ingest infective worm eggs that have been passed through the pet’s feces and left in the environment. The eggs can then hatch in the human’s intestinal tract, and the immature worms can travel to various tissues in the body, including the eyes and brain, potentially causing serious infections.”


Hookworms are the real bloodsucker of the group! They attach themselves to the small intestine and drink the blood of your puppy. If left untreated, they can cause very severe anemia in puppies.

Hookworms are the most common in puppies as they are also transmitted via mother’s milk.


Heartworms are less common in puppies but incredibly difficult to cure. They are solely contracted by mosquito bites. Heartworms lodge themselves in the heart and lungs, reproducing and generally becoming a menace.

Prevention is the very best course of action as once a puppy is infected with heartworms, they are very difficult to get rid of.


This is the name of the worm that puppies have that you are most likely most familiar with. They are long, flat, segmented worms that feed off of the intestine.

These are most commonly contracted via fleas that are also contaminated with tapeworm.


Finally, whipworms are extremely unpleasant. You are most likely to see symptoms of bloody stools and (or) enlarged bowels with whipworm in puppies.

These worms are common in puppies because they can be ingested from contaminated sources, e.g. animal poop, and soil. That said, whipworm isn’t as difficult as heartworm to cure.

Can puppies die if they have worms?

Of course, when you hear “your puppy may be born with worms” you are probably panicking as a dog parent. Your baby may be born sick! That’s an awful thing to hear. But how dangerous is it really?

Well, from my high school days in Biology class, you learn that the parasitic relationship is one where only the parasite benefits. They feed off of your life force whether that be blood, food, or some other benefit that they need from you.

So, it is in the parasite’s interest to keep their host alive. If the host dies, they have no fresh supply to feed from.

That said, with puppies, certain worms can take things a bit too far. Hookworm causes anemia which weakens your puppy immeasurably.

For a growing body, this can be dangerous if left untreated. Roundworm will certainly weaken your puppy as they are stealing nutrients.

Over a long period of time, this can cause health issues that lead to death.

It is not the worm itself that will kill your puppy, but the associated health risks – so a solid de-worming regimen is key to the health and happiness of your puppy. Find out how to do that in the next section.

How to treat worms in puppies

Okay, so we are assuming your pup has the little leeches crawling around inside them. Lovely. Let’s get to work. The first thing to think about is how old your puppy is, because you can’t start worming treatment until they are about 2 or 3 weeks in age.

If you are buying from a breeder or adopting, then usually your puppy will be at least 8 weeks old before you take them home so that will be ok to get started. Ask the breeder or shelter if they have been given any worming medication to date so you can keep track of their progress.

Your vet will guide you as to which deworming medications to use and the dosage. The basics for an effective worming schedule is as follows:

  1. Your vet will give you a recommended worming medicine and the correct dosage. Most worming medicines come in oral solutions for puppies to make it easier. (Try getting a puppy to swallow a tablet – good luck!) You can mix the solution into their food or squirt it directly into their mouths.
  2. For the first time, your vet will likely advise that the treatment is given twice. This is because, if your puppy does have worms, one dose is not enough to kill off the worms entirely. You have one dose to kill the active hatched worms wriggling around right now. Then the second dose kills off the worms that are yet to hatch.
  3. If the treatment has been successful, you should see the remnants of the worms in your puppy’s stool.
  4. Give the medicine as directed every 2 weeks until they are 10-12 weeks old
  5. After reaching 12 weeks old, you can give them worming treatment every month until they are 6 months old. Typically you can graduate to administering worming tablets at this stage.
  6. After reaching 6 months old, be sure to give your growing dog worming medicine every 3 months for the rest of their lives. This is maintenance so don’t be concerned if your dog no longer has worm eggs and severed bodies in their stool anymore. Prevention is generally the best medicine when it comes to parasitic worms in dogs.


Parasites are very strange creations. I am fortunate enough to have never seen the familiar tiny white pieces of a life-sucking tapeworm in my dog’s poop. The thought makes me shudder.

That said, my dogs were rescues and were on strict deworming regimens when I met them. They had very sheltered lives (pun absolutely intended).

But when it comes to puppies, most dog owners will be appalled and shocked to hear that their little one could be born with hookworm or roundworm already squirming in their insides.

Puppies can be born with worms, so it’s just part of the wonders of pet ownership!

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Here are some more tips and hints for new puppy owners.

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Marc Aaron

I write about the things we've learned about owning dogs, the adventures we have, and any advice and tips we've picked up along the way.

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