My Dog Ate a Highlighter: What to Do If It Happens

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.

There’s nothing that gets the adrenaline pumping quite like walking into a room to find your faithful hound, tail wagging, covered in neon splotches.

Yes, that’s right, my dog ate a highlighter.

If you’re reading this with a look of dismay, clearly we’re in the same boat. But don’t despair, you haven’t enrolled in a pet-owner version of a horror movie.

This unexpected incident can actually be an eye-opening journey into canine health and safety.

Stick around if you’ve got a curious canine who’s prone to snack on unconventional treats as I’m here to dispel your worries, offer solutions, and share how to dodge the ‘highlight’ of your dog’s day from taking a toxic turn.

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What Are Highlighters Made of?

It can happen. One moment, your human child is using highlighters to do arts and crafts, and the next thing you know, your fur baby has eaten it as an afternoon treat.

A highlighter is essentially just a plastic casing with a sponge inside, and the said sponge holds the bright ink. 

The problem is, there is toxic stuff in there that is harmful to dogs.

Doggy says, you might be keen to read this too: Dog ate too much Galliprant

What Are the Chemicals in Highlighters?

Do you know the major components of highlighters? One of them is a chemical called fluorescent dye. This gives the ink its vibrant color. 

Various compounds make up the eye-catching dye, including fluorescein, pyronines, and rhodamines. 

The names may sound scary but these chemicals are usually harmless when ingested in small amounts.

Additionally, highlighters may contain solvents that help dissolve the dye and facilitate smooth ink flow. Examples of these solvents are alcohols or glycols, 

You might also find other ingredients in the mix. Highlighters typically have surfactants, humectants, and preservatives to keep the ink stable. 

Are Highlighters Toxic to Dogs?

Are Highlighters Toxic to Dogs

The ink of the highlighter is generally not toxic to dogs if ingested in small amounts.

At most, your pet may experience mild stomach upset or have stained skin or tongue. 

So, if your dog snacked on just one, you shouldn’t worry too much.

The truth is, the plastic casing of the highlighter may pose a greater threat to your pet than the ink itself.

Doggy says, you might wanna read this too: What to do if my dog ate grapes?

What Are the Potential Risks if My Dog Ate a Highlighter?

Aside from the possibility of a stomach ache and temporary stains on the mouth, there is a risk of choking if your dog swallows a large piece of the plastic casing.

The chunk can get lodged in their throat. 

Additionally, the sharp edges of the broken casing can leave cuts inside the mouth and along the gastrointestinal tract if the pieces are swallowed. 

The most serious risk of eating a highlighter though, remains to be blockage in the digestive system. 

Your pet could end up in serious trouble if the plastic pieces go down the wrong way and get stuck in the intestines.

Doggy says, you might be keen to read this too: Gaviscon for dogs

What Symptoms Should I Watch Out for if My Dog Ate a Highlighter?

Your dog may experience mild digestive issues if they eat a highlighter. This can range from an upset stomach to vomiting and diarrhea. 

They may also experience a drop in appetite or difficulty pooping.

Plastic is impossible to digest so your pet could feel full and not want to eat after swallowing the broken pieces.  

If your pet is experiencing pain, you might also observe some behavioral changes. 

Look for signs of unusual tiredness and restlessness. These are signs that a dog is distressed.

Pay particular attention to common signs of gastrointestinal blockage.

That includes severe stomach pains accompanied by repeated vomiting, bloating, constipation, or a complete lack of appetite.

If you observe these symptoms, GO TO THE VET IMMEDIATELY.

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Doggy says, consider reading this too: What to do if my dog ate Babybel wax?

What Should I Do if My Dog Ate a Highlighter?

The first thing you should do is calmly assess what happened.

What exactly did your pet manage to eat? 

If it’s just a few small pieces, they should easily pass through your furry pal’s digestive tract. They shouldn’t be a problem. 

But if your furry pal managed to get its paws on an entire box of highlighters and has ingested quite a lot of plastic, seeking professional assistance is your best bet to addressing this mishap.

Try checking your dog’s mouth for wounds or see if any of the pieces are lodged in their throat.

Next, observe your furry friend for any unusual signs of discomfort or distress. If you notice anything out of the ordinary, consider paying your pet’s vet a visit.

When it comes to inducing vomiting, it is something best left for your vet to decide. Do it only if your pet’s vet asks you to do so. 

How to Prevent a Dog From Eating a Highlighter?

How to Prevent a Dog From Eating a Highlighter

To avoid any more colorful mishaps, it is best to take some measures in preventing your pet from getting their paws on any other highlighters.

Keep them and other art supplies in a safe place. Choose a place that your pet cannot access by climbing.

You can also opt to place all of your supplies in a sealed container to make sure that your inquisitive pet cannot get to them.

Next, supervise arts and crafts time. This way, you’d be able to intervene when your pet pounces on any unattended highlighters. 

To avoid even the minor risk of your furry pal getting an upset stomach from eating highlighters, go for art supplies that are non-toxic and pet-friendly. 

Doing so will ensure that your pet stays safe even if they accidentally ingest your coloring materials.

Doggy says, you might be keen to read this too: Dog ate an ink pen?

Can a Dog Die From Eating a Highlighter?

It is highly unlikely that your pet could die from eating a highlighter.

The ink is generally considered to be safe for ingesting in small amounts and is not a significant poisoning concern.

The plastic casing encasing the ink is a different matter, especially if your dog has ingested a large piece. 

Eating any plastic or other foreign objects can potentially lead to complications such as gastrointestinal blockage.  

Signs of Intestinal Blockage in Dogs

If your dog managed to swallow a large amount of plastic from a highlighter, they run a risk of suffering from intestinal blockage. 

This is a serious situation that might require immediate attention. That is why it’s crucial to know what symptoms to watch out for.

Be wary if your dog is vomiting repeatedly, especially without bringing up any food or bile.

Watch out for abdominal discomfort. Pay attention to signs of pain, such as whining or whimpering when you touch their belly. 

A swollen or distended abdomen may also be a warning sign of a blockage. 

If your dog’s belly appears larger or feels tight, it could indicate that something is obstructing the normal passage of food and waste through the digestive system.

Constipation or difficulty passing stool can also signal an obstruction.

If your dog is having trouble pooping or hasn’t moved their bowel for a couple of days, it may suggest a blockage is present.

A sudden lack of appetite or refusal to eat is also a cause for concern.

Lastly, be alert for signs of lethargy. If the poor pooch appears unusually tired, weak, or less active than usual, go to the animal clinic ASAP.

Doggy says, you might be interested in reading this too: My dog ate a dryer sheet

Treatment of Intestinal Blockage in Dogs

Intestinal blockages can be scary for both you and your furry pal.

To understand the treatment better, here are some steps that your vet will take to address this problem.

  • Your vet will initially do a thorough examination to get a better picture of your pet’s condition.
  • They may run several diagnostic tests to confirm if there is indeed a blockage and exactly where it is in your pet’s digestive system. Expect your vet to ask for X-rays or any other imaging techniques.
  • Finally, the doc will prescribe the appropriate treatment after identifying the location and severity of the intestinal blockage.
  • Unfortunately, surgery is a real possibility. In certain cases, this is the only solution to remove the obstruction. 

Less severe cases may be managed with medication or non-invasive procedures.

Frequently Asked Questions (FAQs)

Is it necessary to induce vomiting if my dog ate a highlighter?

No, it is not necessary. Inducing vomiting should only be done if your veterinarian tells you to. There are cases when the situation can get worse if you try to force your pet to vomit after eating a highlighter.

When should I contact a veterinarian if my dog ingested a highlighter?

You should get in touch with your pet’s veterinarian immediately if your dog exhibits symptoms such as persistent vomiting, diarrhea, abdominal pain, loss of appetite, difficulty breathing, or excessive drooling. 

What if my dog swallowed a highlighter cap?

If your dog swallows a highlighter cap, it’s important to contact a veterinarian promptly. Swallowing a foreign object, especially a plastic cap, can lead to potential complications such as your pet choking or suffering from an intestinal blockage. 

In Conclusion: My Dog Ate a Highlighter

Remember, curiosity may give our dogs a colorful afternoon, but it’s our job to keep them safe.

Armed with awareness and preventative measures, you’re now ready to tackle any highlighter mishaps.

Stay safe!

Before you go, check out these other dog care tips too:

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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!

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