How Big Of A Rock Can A Dog Pass?


If your beloved pet just swallowed a rock, you’re basically looking at two possible outcomes – either he will be able to pass it safely or he will have to undergo surgery, which is quite traumatic and risky for the dog, not to mention hugely expensive.

The million-dollar question is can the dog poop out the foreign object? There is no simple answer to this question. Let’s examine what can happen and what are the chances that your dog will get rid of that rock the natural way.

All the information is intended for a scenario in which your dog appears well with no unusual symptoms. If your pet seems in distress, don’t waste the time reading this and head for the vet’s.

What happens when a dog eats a rock

For a new pet parent it might be an odd situation, but experienced dog owners are well aware of the fact that their four-legged companions are very curious by nature and will swallow most anything, including rocks.

Since you’re reading this, you probably caught your naughty pet in the act. You probably saw him playing with the stone and then it was gone. This is very important as this means you must have some idea how big the rock was and what it looked like.

The good news is your dog didn’t choke on the rock, which can happen with a large or irregularly-shaped dog that gets stuck in a dog’s esophagus.

Now, you might be tempted to think that since the dog was able to swallow it without a problem he’ll probably manage to get it out the other end just as well. Unfortunately, a lot can happen along the way and the rock might not make it to the other end at all.

If it’s a definitive answer you’re looking for, experts say a dog can safely pass a rock that’s less than 1.5 inches in diameter. Some pet owners report their dogs successfully eliminating rocks that were up to 2 in in diameter, but we’re talking about really large dogs and pretty lucky at that.

Your dog’s chances of passing the foreign object also depend on the rock’s shape. A smooth river stone will navigate the dog’s gastrointestinal tract easier than a rock with sharp edges. This type of rock can do a lot of internal damage, destroying the stomach lining or creating an intestinal blockage.

How long does it take for a rock to pass through the GI tract?

Timing is everything when a dog ingests some foreign object. If you’ve just witnessed your dog swallowing a rock, chances are it’s still in its stomach. According to experts, food or, in this case, non-food spends up to two hours in the stomach before moving on to the intestines.

All in all, it can take between 10 and 24 hours for the foreign object to make it to the other end, if it does, which is not always the case. In some cases,  a foreign object can remain in the stomach for weeks or even months.

How to make your dog throw up

If you believe the rock is small enough for the dog to throw it up, you can try to induce vomiting. Making a dog throw up is easier if he has some (real) food in his stomach. If the dog hasn’t had anything to eat in the past two hours, offer him a small meal and make sure to include small pieces of bread that might help cushion the rock.

The easiest method to induce vomiting is squirting hydrogen peroxide down his throat. Use a plastic syringe (without a needle) or a turkey baster to get the peroxide down his throat. Make sure you use a 3% hydrogen peroxide solution as higher concentrations can be toxic. The recommended dose is 1 teaspoon of hydrogen peroxide per 5 pounds of body weight.

The solution acts like an irritant when it interacts with the digestive acids and the dog will throw up most of the stomach’s content. If it doesn’t work, repeat after 30 minutes. Obviously, you will have to check the mess carefully to see if he got rid of the stone. Hold your nose and good luck!

What can happen if the the rock is stuck in the stomach

In many cases, an ingested rock can remain in the dog’s stomach for a longer period. Actually, there have been many cases where the owner had no idea what’s wrong with his dog until a rock or several were discovered during a clinical exam.

One of the biggest issues here is that often enough the rock is too big to pass through the pyloric valve that leads from the stomach to the intestines, in which case it is pretty much stuck. If the dog didn’t throw it up either, the only solution is surgery.

What can happen if the rock is lodged in the intestines

On the other hand, even if the rock is small enough to pass through the pyloric valve there’s no guarantee it is on its way out. A rock with rough edges can damage or puncture the intestines causing a massive infection, something that will require intensive and very costly treatment for your pet.

It is also possible for the rock to become stuck once it reaches the ileocecal junction, where the small intestine meets the large intestine (the colon). If it can get to the colon, chances are it will be eliminated safely, although it might prove a painful process. If it gets lodged anywhere in the intestines it will generate an intestinal blockage, which is a very serious matter as, left untreated, it can lead to death.

Warning signs you should watch out for

When your dog eats a rock small enough for him to swallow safely, you’re not dealing with a medical emergency. At least, not immediately. However, you should keep your pet under constant supervision for the next 24 hours and watch for any changes in his normal habits. The only situation when you should head for the vet immediately is when your pet swallows coins or small batteries, which can be toxic. A stone in itself does not pose such risk, therefore you can afford to wait.

  • For the following hours after the incident, recurring bouts of vomiting (not induced by you) usually indicate that the foreign object is still in the dog’s stomach and it causes irritation. If the dog keeps vomiting the next day and there’s no sign of the rock in his poop then you should be really worried as vomiting is also a symptom of intestinal blockage. Here are other signs to watch out for:
  • Distended bloated stomach, tender to the touch
  • Diarrhea
  • Loss of appetite
  • Constipation
  • Lethargy

Watch your pet’s bowel movements, but keep in mind that if he has a partial blockage he might still be able to poop, although less than normal. A partial obstruction is just as dangerous as a complete blockage. If you notice any of the symptoms above or other signs of distress – it’s your pet, you know when he’s unwell – call the vet immediately.

What to expect at the vet

The vet will check your pet’s vital signs and will try to feel his stomach and the abdominal region. However, this sort of exam is often inconclusive and the best way to establish a diagnosis is for the dog to have some X-rays to discover where the offending object is situated.

If the doctor feels there’s a chance the dog will poop out the stone he might recommend a wait and see approach. However, if the rock is over 2 inches in diameter he will probably propose surgery to have it removed. That’s going to be a blow to your finances as such surgery costs upwards of $1,000. Many pet owners will prefer to wait a bit more and if your dog’s condition is not particularly worrying you can certainly do so. Seeking a second opinion might put your mind at ease so you could check with another vet.

On the other hand, you don’t want to wait too much as an intestinal blockage can be lethal to your pet. An obstruction can interfere with normal blood flow and can cause intestinal tissue to die. In this case, the affected part of the intestines will have to be removed during surgery. A sharp-edged rock can puncture the intestines and cause peritonitis. 

Bottom line, if the rock gets to the intestines it can do a lot more damage than in the stomach. And surgery for intestinal blockage is more expensive, up to $2,000. In case your dog develops peritonitis, he will probably need to be hospitalized and will need massive antibiotics doses, so we’re talking about a lot more money than stomach surgery.

Don’t wait until it’s too late

A dog with a full intestinal blockage will die in 3-4 days if he doesn’t get medical treatment. At the same time, if your dog has a partial obstruction he might waste away in front of your eyes. It might take longer, three to four weeks, and the symptoms might appear less severe, but the outcome is almost always negative. In other words, if nothing happens after 24 hours and the rock is not eliminated one end or the other, don’t wait for nature to take its course as it might be a turn for the worse.

Key Takeaway

Rocks are among the most common foreign objects dogs usually eat, so you shouldn’t be surprised if your pet just did that. If the rock is small enough, less than 1.5 inches in diameter, there’s a good chance the dog will pass it safely. If you feel confident the rock was small and smooth you can afford to wait and see what happens. It should be out in the next 24 hours.

If that’s not the case or if you’ve watched your dog swallowing a pretty big rock, don’t hesitate to call the vet. One thing you want to avoid at all costs is the foreign object being lodged in the intestines, as the consequences can be lethal.