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Dog Ate An M&M [What Do You Need To Do Now?]

Have you come to the sudden and perhaps alarming realization that your dog has eaten an M&M? Or worse, multiple M&Ms. Not sure how concerned you should be or how to respond? It is chocolate, after all. Well, here is how you are going to want to proceed.

So, what should you do if your dog ate an M&M? If your dog has eaten a single M&M, they should be fine, and there is nothing that you will likely need to do. However, several, or a full packet, may cause digestive upset resulting in diarrhea and vomiting. Close monitoring for the next 24 hours is advised. Contacting a vet may be required. 

For the most part, this is not something that should be a cause of immediate alarm.

But it certainly does come down to context.

The risk is ultimately in the dose.

But what is a toxic dose can vary quite dramatically between dogs, as we shall continue to explore in the sections below.

What Happens If A Dog Eats An M&M?

In the majority of cases, nothing will happen if a dog eats a singular M&M. However, the smaller the dog and the more that is consumed, the higher the chances of them experiencing ill effects. 

Either way, you should keep a close eye on your dog.

See how they respond.

That’s because not all dogs will react in the same way. It will likely affect them differently.

That’s because a dog’s health, individual sensitivity, size, activity, among other variables, will all impact how they are able to process them.

But what do they need to be able to process?

First and foremost, there is all the fat and sugar (which can be problematic on their own).

From there, M&Ms (and chocolate in general) contain two compounds that are toxic to dogs in sufficient quantities; these are theobromine and caffeine.

The reassuring news is that it takes, on average, a fairly large amount of each one to cause a toxic reaction.

We are talking about multiple M&Ms here—likely around a bag, + worth.

Now you could try to work this out yourself, but it’s actually much easier to use this useful chocolate toxicity calculator to find out what a dangerous dose is for your dog and your context.

Just consider that if your dog has consumed a toxic dose, any side effects will likely arise within 6-12 hours after consumption.

So, the best thing you can do if your dog has eaten some M&Ms is to be extra vigilant during this time to see how they respond.

Most of the time, you shouldn’t notice any adverse effects.

But depending on how much they have eaten, you will want to look out for symptoms such as:

  • General lethargy,
  • Lack of appetite,
  • Shaking,
  • Increased Body Temperature
  • Bloating,
  • Gas,
  • Diarrhea,
  • Vomiting.

These kinds of symptoms.

If you do begin to notice them, then you should contact your vet.

Otherwise, you can always contact the pet poison hotline. 

Their expertise can prove invaluable, too, helping to identify how much of an emergency it really is.

Now, for the most part, this is for the extreme cases.

For most of you reading, a little close monitoring should suffice.

Along with keeping your dog well hydrated, well-fed, and providing general good care – just as you usually would!

Will One M&M Hurt My Dog?

One M&M is very unlikely to harm your dog. The amount of chocolate (and therefore theobromine/caffeine) is negligible and unlikely to cause harmful effects, even in younger, smaller dogs. 

That being said, just because one M&M is unlikely to harm your dog physically, this does not mean you should ever give your dog one.

It can have psychological repercussions if you do.

For instance, by giving your dog an M&M, you are essentially training or rewarding your dog that this is good food.

Or at the very least, that this is a food that they can eat.

And therefore, should the opportunity ever arise for them to be able to consume some of their own accord (they see them lying around on the counter, for instance), they’ll be much more likely to proceed.

So absolutely do not feed your dog M&Ms, chocolate, or other inappropriate foods for that matter.

Do not build up that association.

Purchase purposefully designed, and healthy dog treats; they’ll be far more enjoyable for your dog anyway 👇

Newman's Own Beef Jerky Treats for Dogs, Original Recipe, 14 oz Bag
  • Made with grass-fed whole muscle beef
  • Delicious meaty flavor dogs love
  • High in protein and naturally preserved with no artificial colors or flavor enhancers
  • Free of grains, corn, wheat and soy
  • Resealable 14 oz. pouch helps maintain freshness


If your dog has eaten an M&M, then first and foremost, there should be no need to panic.

Multiple or a bag of M&Ms, then it could be a little more serious.

In fact, your response should be entirely dictated by the amount your dog has eaten.

One here and there will likely not need any further action.

But any substantial consumption or signs of toxicity, you should act swiftly and contact the pet poison helpline or a vet.

Either way, don’t take any chances here.

Not all dogs will react the same way.

Not all dogs can handle nor process food the same way.

So remain vigilant and respond accordingly.

Oh, and try not to feed them again.

They just do not do a dog any good.

And if you left one lying around or a packet on the side – then you need to try to be a little more mindful and careful.

Dogs are very clever and resourceful when it comes to getting food.

It’s just what they do.

Related Questions

How Many M&M’s Are Toxic To Dogs?

The amount of M&Ms that is toxic will vary by dog. For most healthy adult dogs, 1-2 M&Ms are unlikely to cause chocolate poisoning. However, ingestion of more than 0.5 ounces can put a dog at risk. Equally, very young, very old, small, or dogs in poor health are more at risk from consumption. 

Concerned or wondering what other things your dog can/cannot eat. Check out my related guides below: