Plants And Animals

Chemistry Behind Chocolate Poisoning: Why Is Chocolate Bad For Dogs And Cats?

The root cause of chocolate poisoning in dogs and cats is the presence of theobromine. A small dose of theobromine can make your dog sick, very sick.

Chocolate undoubtedly is one of the most popular food types today and several researchers have shown that chocolate can be beneficial to our health. For example, eating chocolate, especially dark chocolate, can help restore arteries’ flexibility and prevent white blood cells from sticking to the walls of blood vessels. This flexibility to arteries can be good for people with cardiovascular disease such as atherosclerosis. Beside the said benefit, chocolate is a favorite treat for many. So how could something that is so good and tastes so delicious to humans can be so bad for dogs (and cats)?

Chocolate contains compounds such as theobromine, phenylethylamine, tryptophan, phenols, catechins, and anandamide. Of all these components, ACS Reaction points out that theobromine is the central culprit to chocolate’s toxicity to dogs.

Theobromine is so much similar to caffeine in so many ways, but it has a lesser impact on the human central nervous system compared to caffeine. Although it is not as addictive, it has been regarded as the compound that make us get addicted to chocolate.

Also like caffeine, theobromine blocks adenosine from reaching receptors in our brains that regulate wakefulness. Even in small doses, it increases heart rate and flow of oxygen and nutrients to the brain. But in dogs, the effect is different because unlike humans, dogs don’t metabolize theobromine very well. Its effects last longer and this could mess up a dog’s central nervous system.

Once the dog has eaten chocolate, symptoms of theobromine or chocolate poisoning such as high temperature, diarrhea, seizures, vomiting, rapid breathing, increased heart rate, etc would start to show. It’s been claimed that for the symptoms of theobromine poisoning to set in, it generally takes 6 to 12 hours depending on the size of the dog and amount of chocolate the dog has eaten.

Chocolate poisoning in dogs and cats happens because of theobromine. Theobromine has even harsher effects on cats, but cats don't like chocolate and they can't taste sweets.
Chocolate contains theobromine which is toxic to dogs and cats. Theobromine has even harsher effects on cats, but cats don’t like chocolate and they can’t taste sweets.

LD50lethal dose (of a toxic compound, drug, or pathogen) – is the individual dose that will kill half of a test population. Lethal (LD50) doses of theobromine for dogs is 300 mg per 1 kg and for people, it’s 1000 mg per 1 kg, which is over three times more. Should you wonder why chocoholics aren’t afraid of eating too much chocolate? Not anymore.

Different kinds of chocolate have different concentrations of theobromine. For example, milk chocolate contains about 0.02% (60 mg per 1 oz) of theobromine and dark chocolate contains about 1.4% (400 mg per 1 oz) of theobromine.

So for a dog that weighs 20 kg, it would take 100 ounces of milk chocolate and 15 ounces of baker’s chocolate to reach the lethal dose (LD50). Here, we are talking only about the lethal dosage. Even a small dose of theobromine can make your dog sick, very sick. As mentioned above, the degree of theobromine poisoning depends on the size of the dog. So, the smaller the dog, the higher the risk of poisoning.

What if your dog eats some chocolate? Well, you can make your dog puke up by ingesting hydrogen peroxide. Inducing vomiting can be hazardous, so it is recommended to contact veterinarian first before doing so, so that the appropriate dose of hydrogen peroxide is ingested.

Theobromine has even harsher effects on cats; but good news, they are not after chocolates. The sweet receptor in humans is made up of two coupled proteins generated by genes, Tas1r2 and Tas1r3. However, cats do not have 247 base pairs of the amino acids that make up the DNA of the gene Tas1r2. As a result, cats cannot taste sweets.

10 comments

  1. Someone told me something similar happens to humans who eat few too many raw runner beans and french beans. Its my favorite thing to .. graze around the garden in the summer!! but after hearing someone being taken to a&e and having horrible things happen to them, decided to give this a miss. You need to boil green beans for 20 minutes to deactivate the active ingredient. Probably something similar in Cassava.

  2. Thanks for the information. I remember a Valentine’s Day when we took our dog to the animal hospital after he consumed a bag of chocolate. He was fine, but were much more careful after that. I knew chocolate could be toxic but didn’t know why.

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