How Much Chocolate Is Toxic for Dogs? - Petful

No Chocolate (or Ribbons) in This Stocking

Between chocolate-induced comas in dogs and having to surgically remove ribbons from cats, this veterinarian has her hands full during the holidays.

Chocolate is toxic to dogs
Wally tries not to be tempted by the chocolate.

My pets have performed the typical holiday antics, as in most households.

Yeah, yeah, the fully decorated Christmas tree that falls to the ground with a kitten in the middle (safe, pretending he’s an ornament); missing guinea pig found chewing on the Christmas light wires and managing to darken only the middle of the tree (not safe, but Juanita was absolutely fine — no electric shock); and Bitsy, that obese coonhound, parading in front of my veterinary hospital with a foreign object hanging from her rectum.

I had wondered what happened to that bag of turkey innards. No giblet gravy that year. In all my 20-plus years of practicing veterinary medicine, I never saw another dog ingest the whole bag of turkey parts and pass it without a moment of gastrointestinal upset. Yes, Bitsy had an ironclad stomach, and the eating disorder to prove it.

What is a true danger to your pet this season and how can you avoid it? Far and away, the most emergency calls I get this time of year (and Easter and Halloween) are questions about chocolate ingestion.

Chocolate can be very toxic to your dog (and cat), but the amount and the type of chocolate is critical in assessing whether or not you have to panic.

Here are some golden rules to place on your refrigerator while you’re waiting for your vet to call back. With this information, maybe you don’t have to panic at all.

Golden Rule #1

ASPCA Animal Poison Control CenterWith any poisoning or toxicity question, know your pet’s approximate weight and the best guess as to how much of the toxin your pet may have ingested.

If you ever have to make a call to animal poison control, 1-888-426-4435, it’s almost a waste of money ($65 phone call) if you don’t have a general idea of the amount of the offending substance.

And you don’t have to break your back holding your pet while you stand on your scale. Try to round their weight to the nearest 10 pounds of body weight: 20, 50, 100 pounds, etc. Get the best idea of the most the pet could have eaten: three 16 oz. bags of peanut M&M’s, 4 ounces of dark chocolate, and so on.

Golden Rule #2

What kind of chocolate was it? The darker the chocolate, the more toxic. Baker’s chocolate is scary; white chocolate is almost nontoxic.

If you’re mathematically inclined, you can follow the following table and get a good idea of the level of chocolate toxicity. You have to know how to convert the chocolate into its toxic form.

How Much Chocolate Is Toxic for Dogs?

If your dog ingests an amount CLOSE to 20 mg of toxic ingredient per pound of dog, you need to call the vet.

How much chocolate is toxic for dogs

To illustrate the math, let’s say you have a 20 pound dog. We’ll call her Cookie.

  • Example 1: Cookie (bad dog!) has eaten 3 ounces of dark chocolate. Dark chocolate contains 130 mg/oz of toxin, as shown in the chart above. So, 3 oz X 130 mg divided by 20 pounds of dog weight = 19.5. Is this a worrisome amount for Cookie? Yes, it’s very close to 20. YOU SHOULD CALL THE VET — or bring the pet to the emergency hospital. Remember, anything close to 20 is an emergency.
  • Example 2: What if this was 3 ounces of milk chocolate? Let’s do the math: 3 oz X 58 mg divided by 20 pounds of dog weight = 8.7. You are not anywhere close to the toxic “magic number” of 20.

Many of my clients panic when their dog eats a few M&M’s or some chocolate brownies. Neither of these products is solid chocolate, so the amount of chocolate ingested is much less and therefore less toxic. The pet may still get an upset stomach or diarrhea, but you won’t have to worry about bringing them to the emergency hospital.

This Just in…

As I am writing this, an emergency call has come in! Not lying!

“Those rotten ——-! They got under the tree, unwrapped the chocolate-covered cherries and ate 16 of them. Oh my God, what do I do?”

First of all, congratulate yourself on having presents under the tree and wrapped. Second, tell me what your dogs weigh and the total number of ounces in the chocolate-covered cherries box.

Her dogs weighed 60 and 40 pounds, and the box of cherries was 8 ounces. You guys are pros now; you know how much chocolate is toxic for dogs — so does she have to worry?

Not at all. Suppose the smaller dog ate the entire box. That’s 8 ounces of candy, some of which is milk chocolate. Even if it was 8 ounces of pure milk chocolate, not counting the cherries and syrup, we’re not even close to a toxic ingestion. 8 X 58 mg divided by 40 (smaller dog’s weight) is just 11.6. And this would be the worst-case scenario, which assumes little piglet dog didn’t share a single bite with big piglet dog. You can relax, because it’s not close to 20.

A Word About Xylitol

Xylitol, the substance found in sugarless gums, sugarless candy and cropping up in many other products, is extremely toxic to animals. The ASPCA Poison Control goes so far as to say that products containing xylitol should not even be in households with pets.

Christmas can be a very hectic time with lots of stuff all over your house, so don’t give sugarless gum as stocking stuffers or have it lying around. Two pieces of gum containing xylitol can be toxic to a small dog!

Now let’s talk about holiday dangers to cats.

Cat playing with ribbon
OG (Orange Guy) demonstrates the improper use of holiday ribbons.

Ribbons and Bows

Ribbons and bows everywhere! You know that cute picture of the kittens in the yarn basket? Well, there’s nothing cute about it. Cats love to play with linear objects of any kind, and a year doesn’t go by when I’m not cutting into intestines removing what is known as “a string obstruction.”

String obstructions are more dangerous than a simple foreign body obstruction (mouse toy, for instance) because of what the string can do.

The cat can swallow the string but some of it often gets caught underneath the tongue. The rest of the string goes down into the GI tract and gets stuck in different sections, causing an accordion-like effect. The surgery to correct these obstructions can be difficult.

In the worst cases, multiple sections of intestine have to be cut into or even removed. If these obstructions go undetected, the string can cut through the intestine like a saw, and the infection this causes can be fatal (peritonitis).

Often Not Obvious

Many people don’t see their cat playing with or ingesting the ribbon or string. They only know that they have a “sick” cat. The symptoms can be vague to severe: vomiting, lethargy and anorexia to name a few. But since cats can vomit at the drop of a hat, the symptoms can be confusing.

X-rays can be suggestive of a string obstruction, but they don’t always give us a definitive diagnosis. Once in a while, I actually find the string under the tongue, so I know I have to take the cat to surgery. You can’t simply cut the string and pull, because you will do more injury to the intestines.

If you have a normally healthy kitty who loses its appetite for more than a day and begins to be reclusive and vomit more than once or twice, it’s time to call the vet. If your cat is vomiting but still has a great appetite and lots of energy, it may not be that serious.

It is more typical for a young playful cat to swallow a linear object, but I have found many older cats with obstructions too. These can be diagnostically challenging because the person may not see such a noticeable difference in their 10-year-old cat who spends most of the day sleeping anyway.

If you are not sure if your cat needs to go to the vet, try to get a clear picture of its behavior when you call your vet. Separate the cat in question if you have a multi-cat household, so you can determine if the kitty is eating, defecating, vomiting and so on. History helps your vet tremendously.

I love when a client comes in and says, “One of my cats is vomiting, but I don’t know which one.” “Don’t worry, Mrs. Ditz,” I say. “I have my veterinary-X-ray-vision-telepathic-glasses right here, and I’m going to peer into your house from my office and determine which of your cats has a tummy ache.”

You can do things at home to save time and money and help the vet and the pet!

Isolate the pet you think may be vomiting with a litter box in an area where you can find vomit easily. Sometimes this may only be clear liquid or frothy foam. I usually suggest an overnight fast to see if mild vomiting will stop if food is withheld. If there is no vomit, offer a bland meal (a small amount of chicken baby food or chicken cat food). Now you have a lot of information to give your vet. Again, if you have a cat that is extremely lethargic and vomiting continuously, don’t mess around; just get the cat to the vet.

A Final Note

Remember that pets can feel the stress of the holidays just like you. Lots of commotion, visitors and strange stuff around the house (not counting your relatives) can all change the behavior of your dog or cat. Try to keep their routine as normal as possible. Feed them what they’re used to at the same time in the same place. “Introduce” your dogs to company, particularly if they are fearful or anxious.

This begins an entire new topic for another article, but when in doubt about your pet’s behavior with strangers, particularly children, DON’T LEAVE YOUR PET UNATTENDED. Although the best situation is to have your pets present, an aggressive or fear-biting dog does not belong at a big holiday party! Try to get them used to a safe place in your house, away from the fray, if you know they get stressed around new people.

Think about it from their perspective: “Why are you playing that loud music and why are there tons of twinkle lights, shopping bags and people wearing reindeer antlers in my house? Why can’t it be the way it used to be?”

Pets are wise. Look forward to January.


This pet health content was written by a veterinarian, Dr. Debora Lichtenberg, VMD. It was last reviewed Dec. 19, 2012.

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