Bringing a new puppy home is an exciting adventure, full of cuddles, curiosity, and learning curves. While I expected teething, potty training, and endless energy, I didn’t realize how essential deworming would be to my pup’s early health. The first time I dewormed my puppy, I was surprised by some of the changes I saw—a bit of vomiting, loose stools, and lethargy.  It caught me off guard, and I began to wonder what was normal and what wasn’t. If you’re in the same boat, this guide will help you understand what deworming in puppies really involves, the deworming side effects puppies to watch for, and how to make the process easier on your little one.

What Is Deworming in Puppies?

Deworming is the process of treating your puppy for internal parasites that often take up residence in their digestive system. These uninvited guests—like roundworms, hookworms, tapeworms, and whipworms—can steal nutrients and even cause serious health issues if left untreated. Puppies are particularly vulnerable, often inheriting worms from their mother or picking them up from the environment. That’s why deworming is one of the first health steps most vets recommend.

Why Deworming Is Necessary for Puppies?

Worms might not sound like a big deal, but they can wreak havoc on a growing pup. In addition to stealing essential nutrients, they can cause diarrhea, vomiting, weight loss, anemia, and even blockages in the intestines of puppies. Some puppies with heavy worm loads may show stunted growth or a pot-bellied appearance. Deworming ensures your puppy grows strong, stays energetic, and avoids long-term complications.

Common Types of Worms in Puppies

Each type of worm affects puppies differently. Here are the main culprits:

• Roundworms – Extremely common in puppies and often passed from mother to pup. They can cause bloating and digestive issues.
• Hookworms – These tiny parasites can enter through the skin or be ingested and may cause anemia or bloody stools.
• Tapeworms – Typically passed on through fleas. You might spot small, rice-like segments in your pup’s stool.
• Whipworms – Less common but still a threat. These can lead to chronic diarrhea and weight loss.

Understanding which type your pup might have helps your vet select the right dewormer and treatment plan.

When Should You Deworm a Puppy?

Puppies usually start their deworming schedule at around two weeks old, with follow-up treatments every two to three weeks until they’re 12 weeks of age. After that, monthly deworming is often recommended until they’re six months old. From there, your vet will likely suggest a routine maintenance plan based on your dog’s lifestyle and risk level.

What to Expect After Deworming a Puppy

After giving the deworming medication, you might notice some immediate reactions. In my case, my puppy experienced mild vomiting and a bit of diarrhea. It was unsettling at first, but my vet reassured me it was all part of the process. In fact, seeing worms in your pup’s stool post-treatment is often a good sign—it means the medication is doing its job and the parasites are being expelled.

Common Side Effects of Deworming in Puppies

Here are some of the most typical side effects you might see:

• Diarrhea: Soft or runny stools are the most common response, usually resolving in a day or two.
• Vomiting: Some puppies might vomit shortly after treatment. This is usually brief but worth monitoring.
• Lethargy: Your normally bouncy pup might seem sleepy or sluggish for a day or so.
• Loss of Appetite: A skipped meal isn’t unusual post-deworming.
• Visible Worms in Stool: A somewhat gross but reassuring sign that the medication is working.
• Drooling or Foaming: Some pups react to the taste of the medicine with excessive drooling.

Most of these are short-lived and nothing to worry about. But it’s always important to monitor your puppy closely.

Are Side Effects Normal or a Cause for Concern?

Mild side effects are common and generally harmless. However, it’s important to know when to be concerned. If your puppy is vomiting repeatedly, has diarrhea that lasts more than two or three days, refuses to eat or drink, or puppy shows signs of dehydration (dry gums, sunken eyes), it’s time to call your vet. Also, any signs of an allergic reaction—such as facial swelling, hives, or breathing trouble—require immediate attention.

How Long Do Deworming Side Effects Last?

In most cases, any side effects will show up within the first 24 hours and disappear within two or three days. In my experience, the worst of it was over within 48 hours. Keep in mind that every puppy reacts differently depending on their age, overall health, and the type of worm they’re being treated for.

Tips to Help Your Puppy Recover After Deworming

There are a few things you can do to make the recovery period more comfortable:

• Keep fresh water available at all times to help prevent dehydration.
• Feed a bland, easy-to-digest diet like boiled chicken and rice if your pup’s tummy is upset.
• Let them rest – extra naps are perfectly fine during recovery.
• Watch their stools for worms, blood, or continued looseness.
• Avoid strenuous activity or training until your puppy is back to normal.

These simple care steps can make a big difference in how smoothly your puppy recovers.

When to Contact a Veterinarian

Err on the side of caution and call your vet if:

• Diarrhea is bloody or lasts more than three days
• Vomiting doesn’t stop within 24 hours
• Worms are still visible in stool after multiple treatments
• Your puppy becomes unusually weak or unresponsive
• Any allergic reactions occur (swelling, difficulty breathing)

You know your puppy best—if something feels off, trust your instincts.

How to Prevent Worms in the Future?

Once your puppy is dewormed, your next goal is prevention. Here’s what I do now:

• Stick to a regular deworming schedule with vet-recommended medications.
• Clean up poop in the yard promptly to prevent reinfection.
• Use flea prevention since fleas can transmit tapeworms.
• Avoid high-risk environments like dog parks until your pup is fully vaccinated.
• Get routine vet checkups to catch any issues early.

These habits can help keep parasites at bay and your puppy thriving.

Myths and Misconceptions About Puppy Deworming

As a first-time dog owner, I ran into a lot of misinformation. Here are a few myths to ignore:

• “One deworming is enough.” Not true. Puppies need multiple rounds to be fully clear of parasites.
• “Indoor puppies don’t get worms.” Worms can find a way in through contaminated shoes, objects, or even from their mom.
• “Side effects mean the dewormer is dangerous.” Most side effects are expected and temporary.
• “If you see worms, the medication didn’t work.” Seeing worms in the stool is often proof that it is working.

Being informed can save you a lot of stress.

FAQ: Deworming Side Effects Puppies

1. Can puppies die from deworming?

It’s extremely rare. With proper dosing and veterinary guidance, deworming is very safe.

2. Is vomiting normal after deworming?

Mild vomiting can happen. If it continues or worsens, contact your vet.

3. Should I feed my puppy before giving dewormer?

Some medications should be given with food. Always follow your vet’s instructions.

4. How do I know if deworming worked?

Visible worms in stool, improved appetite and energy, and a clear vet check are all good signs.

Final Thoughts

Going through the deworming process with my puppy taught me a lot. At first, I was anxious about every small symptom. But I learned that mild side effects are normal and usually short-lived. More importantly, I realized that regular deworming is vital to my dog’s long-term health. If you stay informed, work closely with your vet, and know what to watch for, you’ll handle this part of puppy parenting like a pro. It’s one of those essential, behind-the-scenes tasks that help your dog grow up healthy and happy.