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My Dog Ate Cardboard: Should I Be Worried? Our Vet Answers

Written by: Dr. Maria Zayas DVM (Veterinarian)

Last Updated on April 4, 2024 by Dogster Team

black dog with tissue cardboard in its mouth

My Dog Ate Cardboard: Should I Be Worried? Our Vet Answers

What is it with cardboard boxes? Cats love to sit in them, and dogs love to shred them. What makes cardboard so special? When a dog decides to eat some of the cardboard they’re chewing on, how big of a deal is that?

Most of the time, if a dog eats some cardboard, it’s no big deal. If they eat a lot or they have really bad luck, though, this material is an obstruction risk to worry about, so here’s what you need to know about the situation.

Why Do Dogs Eat Cardboard?

Of all the items in your house, why would a dog choose to eat cardboard? It isn’t made of anything nutritious, it doesn’t smell like an animal, and in theory, it doesn’t taste good, so why do many dogs love to rip it up and swallow it?

Cardboard tends to be popular for a few reasons. In terms of chewing, it essentially has a good mouth feel, allowing them to chew into some texture, like with rawhide. It usually makes some satisfying sounds as they do this too.

Cardboard is used in the packaging for many dog toys, and if you have cats, their toys, scratchers, and houses. A dog may already be associating it with a toy, which they would normally put in their mouth and are also at risk of ingesting.

Cardboard boxes, in particular, can have some interesting smells on them after going through the mail system. They may even have something on them that a dog likes, which significantly increases the chances they decide to eat the cardboard instead of just chewing on it.

Anxious dogs will do what they can to self-soothe. Bored, anxious, scared, stressed dogs left to their own devices may start chewing on cardboard simply because it’s available and satisfying to chew. With nothing else to do and an abnormal mental state, deciding to eat things around the house, including cardboard, isn’t abnormal.

Lastly, some dogs have a mental inclination to eat things that aren’t food. This condition is called pica.

black dog in a cardboard box
Image By: Erda Estremera, Unsplash

What Is Pica?

For dogs that don’t seem to know not to eat non-food items rather than just chew on them, their disorder is known as pica. Dogs with pica may simply have an interest in eating things they shouldn’t, but sometimes this can be due to nutritional deficiencies.

To decide to eat the cardboard rather than just chew on it, a dog usually needs to be bored or have pica unless that cardboard has food on it in some way, like a pizza box.

Dogs with pica can cause themselves a lot of harm, breaking teeth, ingesting toxins, breaking out of areas, and eating obstructive materials that require surgery to remove. If you have a dog with pica, it is important to carefully regulate their environment for their safety and work with your veterinary team and a trainer or behaviorist to get to the bottom of their reason for having pica, so you can help them if possible.

Is Cardboard Toxic to Dogs?

The good news is if your dog does eat some cardboard, you don’t automatically have a problem, and this is mostly because cardboard isn’t toxic to dogs. While it isn’t impossible for cardboard to have something on it that is toxic to dogs, usually, that wouldn’t be in a quantity large enough to hurt them.

a stack of cardboard
Image By: JustynaKoniecz, Pixabay

What to Worry About When Your Dog Eats Cardboard

The risk of a dog eating cardboard is that it can get stuck in their stomach or intestines. Cardboard isn’t food, and they can’t digest it. Eating small amounts or small pieces is usually fine. It isn’t a sharp object and will usually pass through their GI tract unnoticed or, at the worst, cause some mild GI upset.

If a dog is swallowing large pieces of cardboard or eats a lot of it, the cardboard can get lodged somewhere in the GI tract, usually the bottom of the stomach or the small intestines, which can be an emergency situation.

In a normal GI tract, rhythmic contractions throughout the GI tract and strategically placed sphincters keep food, which becomes digesta, moving onward through the GI tract until it is expelled as poop. A GI obstruction occurs when something is stuck in the GI tract and stops being moved forward by those contractions.

A GI obstruction can be partial or complete. In most cases, the GI tract continues to contract even though something is stuck. In a partial obstruction, either some fluid and digesta, can still make it past the obstruction, just slowly with a lot of painful inflammation and gas build-up, or the obstructed object does continue to move, but much more slowly, again causing pain, inflammation, and bloating.

Complete obstructions occur when something is stuck and not moving, and nothing else is really getting around it either.

What Are the Signs My Dog Is Ill Because They Ate Cardboard?

Whenever a dog eats anything outside their normal diet, they are at risk for mild signs of GI upset, such as diarrhea, maybe a little vomiting, mild lethargy, or inappetence. This may develop within a day or so of your dog eating some cardboard.

If a dog is experiencing a GI obstruction, either type, after ingesting cardboard, they will likely stop passing stool and vomiting. If a dog can’t keep anything down and is vomiting anything you give them, even water, that is a bad sign. If a dog is given anti-nausea medication also and still can’t keep anything down after eating some cardboard, that is a really bad indication that they have an obstruction. These dogs will also usually be lethargic and have tense, painful abdomens. You may see them trying to stretch their bellies to relieve pressure (unsuccessfully), may be vocalizing, or collapse entirely.

If a cardboard ingestion obstruction goes untreated for too long, the wall of the area of the GI tract it is in can die from the pressure and inflammation around the cardboard and cause a leak. Leaking ingesta, stomach acid, or feces into the abdomen will often cause a dog to become extremely painful in the belly, very lethargic, and they need to go to the ER immediately.

Dog vomit in the living room
Image Credit: A-photographyy, Shutterstock

How Is Cardboard Ingestion Treated?

For mild cases with minor GI upset, a bland diet is usually enough to help these dogs recover. If needed, a veterinarian can provide help with GI protectants, anti-diarrheal or anti-nausea medication, and sometimes even appetite stimulants for dogs feeling under the weather.

If a dog has a GI obstruction after eating cardboard, that needs to be removed one of two ways, both under general anesthesia. An endoscopy can be performed if the cardboard is in the esophagus or stomach, in which a camera is passed through the upper GI tract to the object, and it is grabbed with the scope to pull it back out the dog’s mouth with no incision needed.

Otherwise, in cases where this cannot work or when endoscopy is unavailable, the dog will need surgery to remove the cardboard and potentially remove any dead GI tract tissue damaged.

How Do I Keep My Dog From Eating Cardboard?

While in most cases, nothing bad happens when a dog eats cardboard, if that description of GI obstructions has you worried, you may want to know if there’s a way to train your dog not to eat cardboard.

While it can be tricky to teach a dog to simply not eat cardboard specifically, there are some ways to intervene. By working with a trainer or behaviorist, you can identify possible triggers like boredom or separation anxiety that may be responsible for the behavior. A veterinarian can also screen for potential nutritional deficiencies. These changes may help your dog to learn not to eat cardboard going forward.

For many dogs, it’s impossible to train them to never eat cardboard when unsupervised within the limits of the average family home and training schedule. Setting these dogs up for success instead of not leaving out cardboard when you aren’t supervising them, securing cabinets, trash cans, and your yard can be the best way to keep this from happening.

If you are home and would like to unpack impulse purchases in peace, training a “leave it” command for your dog can be very helpful. If they can be consistently relied upon to not eat something when you ask, that can make the home a lot safer for your pup.

boston terrier dog at clinic with owner
Image By: Ground Picture, Shutterstock

Frequently Asked Questions (FAQs)

How long does it take to know if my dog has an obstruction after eating cardboard?

Usually, dogs will start to show signs within 12 hours, but it can take a couple of days, especially if initial signs are subtle or they start with a partial obstruction.

Can I give my dog something to help them pass the cardboard they ate?

While there are some examples of things you can give a dog to help them pass foreign objects like cardboard, it is best to have them checked by a veterinarian first since doing this isn’t always recommended depending on what they ate, when, and how sick they may be. If a veterinarian thinks it’s a good idea, they can recommend their favorite home treatment after checking the dog first.

Veterinarian examining pomeranian dog with xray
Image By: GoodFocused, Shutterstock

How much does it cost to remove a blockage from a dog?

Cost can vary widely as different procedures may need to be done, how long a dog requires hospitalization before and after differs case to case, and the cost is highly dependent on the region you live in. Generally speaking, these procedures or surgeries cost at least $1,000 but can climb even higher than $10,000 after that in some cases.

Summing Up

Most of the time, when a dog eats cardboard, it’s no big deal and they never show signs of a problem. If the cardboard, which is paper that they can’t ingest, doesn’t sit right with their stomach, they may experience some mild diarrhea, vomiting, or inappetence. In severe cases, the cardboard can get stuck in their GI tract, causing a GI obstruction, which can be an expensive and potentially fatal medical emergency.

If you know your dog ate cardboard, it is best to decide how much they ate if you can tell. Unless a dog is already acting sick or you know they ingested a significant amount, it is usually okay to not do anything unless a problem arises. Be sure to watch your dog carefully over the next few days, checking their stool for confirmation they’re passing the cardboard and watching for the first signs of a problem.

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Featured Image Credit: taylordeasmelesh, Unsplash

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