Dog Ate Montelukast [Can I Give My Dog Singulair?]

Zack Keithy, our author, is a certified veterinarian technician (UC Blue Ash) for over 6 years (contact him here). The articles written here are based on his expertise and experience, combined with a review by our expert vet reviewers including Dr M. Tarantino. Learn more about us here.

Ever had one of those heart-pounding moments when your furry friend decides to devour something they shouldn’t?

Trust me, I know very well it’s a rollercoaster of emotions.

Picture this: it’s a peaceful evening, you’re chilling on the couch, and suddenly you realize that your beloved canine companion has just indulged in an impromptu Montelukast buffet.

Not cool!

In this post, I’m here to walk you through this mini-crisis if your dog ate Montelukast and provide you with solutions to get this situation sorted out, fast.

Medical Questions? Talk to a Veterinarian 24/7.
Connect one-on-one with a licensed vet who will answer your questions in minutes.

Ask a Vet Now or Schedule a home visit

*Article may contain affiliate links to retailers like Amazon and Chewy. Learn more on our disclosure page.

What is Montelukast (Singulair)?

If you or someone you know has asthma, you’ve probably already heard of Montelukast. Well, it goes by the name “Singulair” since it’s sold under that brand too.

Most people know Montelukast as a long-term oral medication for asthma, but let me tell you that it’s also very helpful in fighting allergic reactions!

It truly does wonders for making breathing more comfortable, and I must say, it’s quite a helpful approach to handling asthma and allergy symptoms.

Just pitching a side note here! Montelukast will only work right if you take it every day with the dosage prescribed by your doctor.

I’ve heard that it causes some side effects in some people, and it’s not an OTC drug so you need a prescription from your doctor before you can buy it.

Doggy says, you might be keen to read this too: Does Proin kill dogs?

Can I Give My Dog Singulair?

Can I Give My Dog Singulair

Yes, you can give your dog Singulair, BUT, you gotta get your vet involved before administering this drug to your pup!

Like any other medication for humans, Singulair may or may not bring bad effects on dogs.

Although it’s constantly being prescribed by vets to some dogs, how can you be sure your dog won’t experience any negative side effects from it?

Hence, contact your vet first before giving your dog Singulair. Let’s just say that it’s to avoid more health issues.

Singulair works the same for humans and dogs, y’know. It helps deal with allergies and asthma symptoms.

But dogs and humans have different systems, don’t they? So you’ll have to be extra cautious with giving Singulair to your dog.

I know it seems easier to just give your dog any available medication you have at home, but trust me, don’t do it without professional advice.

Hey there, sorry to interrupt but I wanted to tell you about an online vet service I’ve been using for years.

An in-person visit with one is great, but it’s not always an option.

Now, thanks to technology, you can speak to one without leaving your home.

Remote access
Avoidance of travel
Reduced stress for pets
Immediate access to experts
Quick response time
Schedule appointments easily

Got something to ask a vet?
Talk to one anytime, 24/7.


* Don’t use this service for emergencies.

Alternatively, a vet can come out to you instead (exclusive to our readers: use THEVETS15 for 15% off).


Thank you. The rest of the article continues below.

Doggy says, you might wanna read this too: Will Nyquil kill my dog?

Is Montelukast Dangerous for Dogs?

The fact is, I’ve seen many vets prescribe Montelukast to dogs suffering from allergies, but I also heard quite a lot of side effects too.

The thing is, Montelukast can be helpful to some dogs but dangerous to others. You and I can’t generalize this since dogs aren’t all the same.

But human medications can be dangerous to dogs most of the time, especially if the doses given weren’t correct.

Plus, montelukast is an anti-leukotriene class drug as it helps those who have allergies and asthma to breathe easier.

Unfortunately, anti-leukotriene class drugs are known to have side effects on dogs, thus giving Montelukast a chance to be dangerous to some dogs.

Is Montelukast a Steroid or Antihistamine?

Montelukast is NOT a steroid nor an antihistamine. It’s a kind of prescription called “anti-leukotriene.”

Anti-leukotriene fights leukotriene which are chemicals that cause inflammation in your airways during allergy or asthma attacks.

But make no mistake. Anti-leukotriene, steroids, and antihistamines still go hand in hand together.

Let’s just put it this way: steroids and antihistamines are usually the main treatments for asthma and allergies.

However, anti-leukotriene like Montelukast is still prescribed alongside them to make sure the symptoms of allergies and asthma remain under control.

Doggy says, you might be keen to read this too: Clavamox for dogs without vet prescription

What Potential Side Effects Are There for a Dog Taking Montelukast?

Side Effects for a Dog Taking Montelukast

Depression, aggression, anxiousness

It’s usual for dogs to feel depressed, aggressive, and anxious when introduced to a new treatment.

If you’ve recently added Montelukast to your dog’s treatment for allergies or asthma, you’ll notice these behaviors right away.

And I have to add that there are so many articles online proving that Montelukast increases symptoms of depression.

Hence, it’s no longer a surprise if your once joyful dog becomes a gloomy canine that no longer finds happiness in anyone’s company.


The number of people claiming Montelukast causes liver diseases is quite a lot.

Hence, your dog can suffer from jaundice when taking Montelukast on a long-term basis.

If you aren’t familiar with what jaundice is, it’s a condition wherein your dog’s eyes will turn yellowish caused by liver problems.


Since Montelukast is specifically made for humans, dogs may experience diarrhea as a side effect of taking it.

Montelukast is made up of ingredients that may not sit well in your dog’s tummy, causing gastrointestinal issues.


If you gave your dog Montelukast without consulting your vet first, you might give him the wrong dosage.

When this happens, your dog might experience lethargy as it tries to adjust to the drug you’ve introduced to his system.

What is the Risk of Giving Your Dog Montelukast?

Giving your dog Montelukast is risking medicine poisoning, especially if you did so without consulting any vet first.

Montelukast is medicine for humans, not for dogs. Of course, you’ll have to expect different outcomes when your dog ingests it without the vet’s go signal.

Dogs have unique metabolic pathways that are not the same as humans, so your dog may react unpredictably to Montelukast.

When your dog fails to digest the Montelukast properly, there’ll be an increasing risk of poisoning.

Plus, humans and dogs require different dosages too. And if you gave your dog the wrong dose, Montelukast became a toxic chemical instead of medicine.

Signs of Medicine Poisoning in Dogs

Medicine poisoning in dogs is one of the most common threats when it comes to using human drugs on doggies.

Hence, most dog owners are well familiar with this already.

Whether your dog accidentally ingested a human medication or you have inaccurately given him the wrong dosage, it’s the recipe for medicine poisoning.  

There’s also something else you have to know.

Most medicine poisoning only happens when a human medication is ingested by dogs. Medicines specifically made for dogs rarely ever cause poisoning.

Yes, I’m certainly begging you to use dog medications prescribed by your vet instead of using what YOU are using at home.

Watch out for signs of medicine poisoning if you suspect that your dog has taken the wrong dose of medicine, or that he has ingested drugs not suited for his doggy metabolism. 

These signs are usually:

  • Treatment options
  • Vomiting
  • Restlessness
  • Difficulty in balance
  • Cardiac arrhythmia
  • Cognitive impairment
  • Confusion
  • Abnormal thirst

Treatment options

Call your vet right away

Imagine it like asking a friendly expert for help. Tell the vet everything you know: what medicine your dog might have ingested, the amount, and when it happened. 

Your vet will most likely suggest inducing vomiting to give your dog a chance to throw up the medicine.

You’ll be asked to use hydrogen peroxide to make your dog vomit. However, this is a risky thing to do so you have to do it correctly.

Follow whatever the vet says. If he asks you to quickly bring your dog to the clinic, then step on the gas and go.

Activated charcoal

If your dog accidentally ingests something bad in the last few hours, like medicine, activated charcoal comes to the rescue. 

It acts like a magnet, attaching to the bad stuff in your dog’s tummy. This way, it stops the poison from getting into the body. 

If the toxic chemicals take their time to show up like sneaky guests, your dog might need more doses of the charcoal to keep it away. 

So, activated charcoal is like a guardian that stops the bad things from causing trouble in your dog’s belly.

It’s widely available to buy and it can be given to your dog easily.


When your dog ingests medicine that’s not allowed for him, the vet often gives him fluids.

Consider it like drinking lots of water when you’re thirsty. These fluids help keep your dog’s blood pressure steady and make the poisonous medicine less strong by mixing it with water. 

The added fluids in your dog’s body make sure that the medicine is wiped out quickly.

But the vet should be the only one giving such fluids in the clinic since the medicine poisoning might be worse than expected.

In some cases, vets will have to give the dog additional medication to keep the heart beating normally.

Frequently Asked Questions (FAQs)

Should I induce vomiting if my dog has ingested Montelukast?

Usually, your dog will be able to pass the Montelukast within 6 hours. But if you notice a change in his behavior after ingesting it, call the vet for assistance. Never induce vomiting in your dog if it wasn’t recommended by the vet.

Can Montelukast have long-term effects on dogs after ingestion?

Montelukast is a medication designed for humans, so giving it to a dog poses many side effects. Some of these side effects on dogs might be long-term depending on the amount your dog has ingested and whether or not he experienced poisoning in doing so.

How can I prevent accidental Montelukast ingestion by my dog?

You can prevent accidental Montelukast ingestion by your dog if you keep this medication out of your dog’s reach. Place it somewhere he can’t see, smell or reach. Your dog may also think that Montelukast is a treat hence he’ll want to have some. To avoid this, make sure your dog is receiving enough treats so he won’t have to crave something that’s not good for him.

In Conclusion: Dog Ate Montelukast

Remember, your pup’s unexpected gourmet escapades might give you a scare, but armed with the right information and quick thinking, you’ve got this under control.

Stay vigilant, keep your pup’s vet on speed dial, and continue being the awesome pet parent you are.

Here’s to many more Montelukast-free adventures together!

Hey! If you found this post useful, check out these dog care tips too:

You’ve made it to the end, but I hope it’s not the end of our journey. We want to hear your voice! Share your thoughts, problems, suggestions, or anything related to your dog in the comments section. And don’t forget to join our newsletter today too.

Share this post!
Zack Keithy
Zack Keithy

Hey, I'm Zack, the Chief Editor here. I was formerly a Certified Veterinary Technician (CVT) for a good 6 years before moving on to greener pastures. Right now, I am still heavily involved in dog parenting duties, and it is my desire to share all our knowledge with fellow dog owners out there! Connect with me on LinkedIn, or read more about Canine Care Central!

no more bad dog breaths banner