Can rats eat chocolate? Is chocolate poisonous to rats?
Do rats like chocolate in the first place?
Rat owners often have questions like these about rats and chocolate.
After all, chocolate is a delicious treat for humans, so of course we want to share it with our fuzzy little friends – but only if it’s safe.
So can rats eat chocolate? Let’s start by learning a bit more about chocolate itself.
Fun Facts About Chocolate
Chocolate is made by roasting and grinding the seeds of the Theobroma cacao, or cacao tree (sometimes spelled cocoa).
Chocolate is an ancient food, with a history tracing all the way back to 1900 B.C.E., when it was made by the Olmec civilization in south-central Mexico.
Most Mesoamerican people, including the Aztecs and Mayans, consumed chocolate as a beverage. Some even used it as a currency.
Two major events got chocolate to the correct place and time to be made into the solid form we eat today.
First, starting in the sixteenth century, chocolate and cacao seeds were sent over to Europe by Spanish sponsored explorers like Christopher Columbus and Hernan Cortes.
The second step was the start of the Industrial Revolution.
New technology allowed Joseph Fry to, in 1847, use a press invented by Dutch chemist Coenraad van Houten to remove about half of the fat from chocolate, then add back melted cocoa butter.
This made it possible to mold and harden chocolate.
Nowadays chocolate is one of the most popular foods in the world. In 2016 alone, more than 7.3 million tons of chocolate were consumed worldwide.
The average American consumes 11.64 pounds of chocolate a year. In Switzerland, where chocolate is consumed the most, the average person eats nearly twice that amount!
Now that we know a bit more about chocolate, let’s move on to the question that we’re really here to answer: can rats have chocolate?
Does Chocolate Kill Rats?
The substance in chocolate that makes it dangerous for so many pet species is called theobromine.
Symptoms of theobromine poisoning include nausea, vomiting, diarrhea, and increased urination. This can escalate to cardiac arrhythmia, heart attacks, seizures, internal bleeding, and death.
However, this only occurs if theobromine is consumed in a large enough dosage.
The median lethal dose of theobromine for rats is about 1,265 mg per kg of body weight. The median rat weighs about 450 g, so a lethal dose of theobromine would be about 569 mg.
The average female rat can be as small as 350 grams. She would require about 442 mg of theobromine for a lethal dose.
A large male, on the other hand, can weigh up to 650 grams. For him, about 822.25 mg of theobromine would constitute a lethal dose.
But how much chocolate would a rat have to eat to get that much theobromine?
Well, that depends on the type of chocolate. 100 grams of milk chocolate contains about 211 mg of theobromine, while the same amount of dark chocolate contains about 705 mg.
That means that the average 450 gram rat would have to eat about 269 g of milk chocolate – about 1.5 cups of chocolate chips – to consume enough theobromine to be lethal.
Of course, dark chocolate has more theobromine, so that same rat would only have to consume about 81 g of dark chocolate for a lethal dose.
That’s still quite a bit of chocolate, though. It’s almost half a cup of chocolate chips.
Is Chocolate Bad For Rats?
So we’ve seen that a rat would have to eat quite a bit of chocolate for it to be fatal, but it doesn’t require a fatal dose for a rat to get sick.
Unfortunately, we don’t know the minimum toxic dose of theobromine for rats.
We do, however, know that negative health effects start appearing well before signs of toxicity do. After all, just because something isn’t poisonous doesn’t mean it’s healthy.
Too much chocolate can be bad for rats for the same reasons it can be bad for humans: chocolate has a lot of fat and sugar.
Too much of these substances can lead to diabetes and obesity in rats, which are linked to a number of other health issues.
These include pituitary tumors, cardiac health problems, and, in particular, the formation of lipomas, which are fat deposits under the skin which impair the rat’s mobility. Lipomas can develop ulcers and sores, and must be removed surgically.
With that said, chocolate in moderation won’t hurt your rat. It can even be good for them, providing the same mood boosting and pain suppressing effects to rats that it does to humans.
If you want to give your rat chocolate, give them about a chocolate chip-sized amount of milk chocolate as an occasional treat.
Avoid very dark chocolates, which have higher levels of theobromine, and white chocolate, which doesn’t have theobromine but is very high in sugar and fat.
Do Rats Like Chocolate?
So we’ve learned that chocolate is safe for rats in moderation, but would chocolate even appeal to a rat in the first place?
Rats are, once again, like people in that they tend to have a preference for junk food, even to the detriment of their own health.
(That’s just one more reason for you to limit their access to chocolate; they certainly won’t limit their own consumption.)
In fact, giving medication with a bit of chocolate is a great way to get stubborn rats to take their meds.
Can Rats Eat Chocolate? – A Summary
So there you have it, the answer to the question, “can rats eat chocolate?”
Just like people, rats can eat chocolate, but only in moderation to avoid the health risks associated with too much fat and sugar.
While rats enjoy chocolate and can even benefit from a little bit of it, limiting your rat’s consumption of chocolate and other junk foods is essential to giving your pet rat the longest, healthiest, happiest life that you possibly can.
Resources and Further Reading
- American Fancy Rat & Mouse Association, Pet Rats & Mice – General Care.
- Huang-Brown, K. M. & Guhad, F. A. (2002). Chocolate, an effective means of oral drug delivery in rats. Lab Animal, 31(10).
- Rogers, P. J. & Blundell, J. E. (1984). Meal patterns and food selection during the development of obesity in rats fed a cafeteria diet. Neuroscience & Behavioral Reviews, 8(4).
- Schemmel, R. et al (1970). Dietary Obesity in Rats: Body Weight and Body Fat Accretion in Seven Strains of Rats. The Journal of Nutrition, 100(9).
- Wang, Y. et al (1992). Reproductive toxicity of theobromine and cocoa extract in male rats. Reproductive Toxicology, 6(4).