Chocolate toxicity for dogs

Why chocolate is dangerous

It contains theobromine, which dogs process very slowly. The darker the chocolate, the more it contains: dark chocolate and cocoa are the most dangerous, white is almost harmless.

How to read the result

Risk is estimated in mg of theobromine per kg of body weight: below ~20 mg/kg usually mild, above ~40-60 mg/kg serious symptoms may appear. It's only an indication.

Why dogs and we aren't the same

Theobromine is the substance in cocoa, and it's a close relative of caffeine. We clear it in a few hours; a dog takes four or five times as long, so even an amount that would do nothing to us builds up and stays in circulation for a whole day. That's the whole difference: it isn't that chocolate is poisonous in itself, it's that a dog's liver can't get rid of it.

The type of chocolate counts more than the amount

Between one type and another the theobromine content varies by ten or twenty times. Unsweetened cocoa powder and baking chocolate are the most concentrated; dark comes next; milk chocolate has a fraction of it, and a much larger amount is needed to reach a dose that matters; white contains practically no cocoa, so from this point of view it's almost harmless (it's still fat and sugar, which can cause pancreatitis).

The practical consequence: twenty grams of dark weigh more than a hundred grams of milk chocolate, and at home the biggest danger isn't the bar, it's the dark chocolates left in a low box and the cocoa cake left out to cool.

How to read the estimate

The sum is in milligrams of theobromine per kilo of the dog's weight, and this explains the thing that surprises people most: the same half bar is next to nothing for a German shepherd and can be serious for a chihuahua. Below 20 mg/kg it usually stays at vomiting and restlessness; around 40-60 tremors and a fast heartbeat appear; beyond that, the risk becomes serious.

Symptoms aren't immediate: they generally begin between two and four hours later and can last a long time. Waiting for them to appear is the commonest mistake, because it's precisely in the first hours that something can be done.

What to do

Phone the vet with three numbers in hand: the dog's weight, the type of chocolate and the grams eaten, plus the time. This page is there to prepare that call, not to replace it: it's an estimate on average values, and the decision belongs to whoever answers. If you have the packaging, keep it: the cocoa percentage written on it is the most useful piece of information of all.

Nearby tools

For the other dangerous foods, from xylitol to onion, there is Foods dangerous for pets. For weight and food amounts there are Dog calorie needs and Daily kibble amount, and for water Water for dogs and cats.