Gerbil Dietary Questions: Can Pet Gerbils Eat Chocolate?

Chocolate is a very popular treat for humans but is very sweet and high in sugar. Mongolian gerbils are omnivorous and can eat both plant and animal matter. However, some food can’t be fed to gerbils and is even toxic to them. So, can gerbils eat chocolate safely or is it toxic?

Gerbils can’t eat chocolate. Chocolate contains theobromine, a chemical compound, which is toxic to gerbils. All chocolate is also high in sugar and fat, which is bad for your gerbil’s health. As such chocolate is absolutely unsuitable as food or treats for your gerbils.

You might think that a small amount of chocolate won’t hurt your gerbil but this isn’t exactly true. There are cases of toxicity at very low levels of theobromine. Besides that, why would you give something that isn’t nutritional to your gerbils?

Some resources will say that some chocolate doesn’t contain any theobromine and isn’t toxic for this reason. Theobromine is a compound that gives the typical brown color to brown and dark chocolate. But even white chocolate contains trace amounts of theobromine.

Milk and dark chocolate also contains (high) levels of caffeine and contain lactose. Since gerbils are lactose intolerant and can’t handle high levels of caffeine it’s recommended to stay away from chocolate in any form.

Do Wild Gerbils Eat Chocolate?

Chocolate is made from cacao. Cacao is grown on small tropical trees that are native to Central and South America. Today cacao is also grown in other tropical places. These trees need a hot and humid environment to grow.

As you probably already know, gerbils live in arid regions and the Mongolian gerbil is no exception to this. Mongolian gerbils live in a region with grassland, shrubland, and desert and are used to living with only a limited amount of water.

The temperatures in the natural habitat of these gerbils can get up to 50 °C (122 °F) although usually, the temperatures are lower at normal room temperatures. Water is scarce in this region and it definitely isn’t a good place for cacao to grow (just like banana plants) and it doesn’t grow naturally in this region.

So, wild Mongolian gerbils don’t come in contact with cacao. They’ll eat seeds, roots, bulbs, and herbs. When they’re available, gerbils will also eat fruit and insects but this depends on the time of year and the region they live in.

This doesn’t mean that pet gerbils won’t eat chocolate when it’s given to them. Chocolate has a sweet taste and can theoretically be eaten by gerbils (they will usually eat it when fed). However, this doesn’t mean that it’s safe for them to eat.

Nutritional Value of Chocolate

I already mentioned that the nutritional value of chocolate is low for gerbils but this doesn’t mean that they don’t have any nutrients in them. The following nutritional data (for 100 g) comes from FoodData Central:

Total lipid (fat)37.5g
Carbohydrate, by difference47.5g
Fiber, total dietary2.5g
Sugars, total including NLEA40g
Calcium, Ca100mg
Iron, Fe1.8mg
Sodium, Na75mg
Vitamin C, total ascorbic acid0mg
Fatty acids, total saturated12.5g
Fatty acids, total trans0g

Why Is Chocolate Bad For Gerbils?

As you can see in the table above chocolate is high in carbohydrates and fat. It also contains a lot of sugar and is a high-calorie food. When fed to gerbils the high sugar and fat content can lead to obesity and diabetes, if it weren’t for the toxic compound theobromine.

A normal gerbil diet needs to consist of around 16 percent protein and between 6 and 9 percent fat. Chocolate obviously doesn’t provide these levels of protein and fat. I won’t go any further into the nutritional value of chocolate but will give you more information about troublesome compounds in chocolate (from a gerbil perspective):

  • theobromine
  • caffeine
  • milk

As you’ll see there are some compounds in chocolate that can be toxic in small amounts or can at least cause health issues. For this reason, I strongly advise you to NEVER give chocolate (white, milk, dark, or any food that contains chocolate) to your gerbils and to keep them away from chocolate products so they can’t ingest them by accident.


What is theobromine?

Theobromine is a chemical compound that’s present in cacao (and so also in chocolate). It can also be found in other foods, like the leaves of the tea plant. But chocolate has by far the highest levels of theobromine in it. The following estimated levels of theobromine are available in different chocolate and cacao products:

  • cacao powder: 2634 mg per 100 g
  • unsweetened baking chocolate: 1297 mg per 100 g
  • dark chocolate: 500 to 800 mg per 100 g
  • milk chocolate: 214 mg per 100 g

White chocolate contains only trace amounts of theobromine (around 0.1 mg/g according to this research).

Why is theobromine bad for (small) pets?

Humans can consume fairly large amounts of theobromine (250mg). The reason for this is that humans can break down theobromine very efficiently compared to other animals. However, high amounts of theobromine (more than 1000mg) can also lead to headaches and nervousness in humans.

Theobromine is mostly a problem for dogs and small pets. A normal amount of chocolate for humans can cause serious health issues, and even death, for dogs and cats. Small pets are mostly in danger because of their low weight.

LD50 of theobromine

Scientists use the LD50 measurement to determine how deadly a substance is. It’s the median lethal dose which means that that dose kills half of the tested population. Such studies are mostly done on mice and rats but are also known for dogs and cats because these animals usually (accidentally) ingest theobromine (from chocolate products).

There is currently no published research that has determined the LD50 of theobromine for gerbils. Since there are no studies of the LD50 of theobromine in gerbils we can only compare with other animals that were subject to studies.

AnimalLD50 Theobromine (source)
Rat1265 mg/kg
Mouse837 mg/kg
Dog250–500 mg/kg
Cat200 mg/kg

The LD50 of theobromine in rats and mice is fairly high, even comparable to that of humans. However, gerbils are small animals and can easily get too much theobromine from a small piece of chocolate.

Let’s hypothesize that the LD50 of theobromine for gerbils is 1000 mg/kg. An adult gerbil can weigh up to 130 grams. This means that ingesting 130 mg of theobromine can cause serious health issues and even death.

A dose of 130 mg of theobromine can be compared to eating:

  • 15 g of dark chocolate
  • 60 g of milk chocolate

However, the average weight of a gerbil is around 60 g which halves the above-mentioned amounts. Younger gerbils weigh much less and would reach the hypothesized LD50 with a small piece of milk or dark chocolate.


How much caffeine is in chocolate?

Besides theobromine, there’s also caffeine in milk and dark chocolate. White chocolate doesn’t contain caffeine just as it only contains small trace amounts theobromine.

Dark chocolate not only has the highest theobromine content but also the highest caffeine content. Dark chocolate has up to 70 mg of caffeine per 100 g. Milk chocolate contains around 40 mg of caffeine per 100 g.

Why is caffeine bad for (small) pets?

Caffeine is, just like theobromine, a methylxanthine. Both are the main toxic compounds in chocolate. In combination, they form a danger for your gerbils. Small amounts of caffeine seem to have very little positive effects on the operant behavior of gerbils.

There is little published research that has studied the effects of caffeine on gerbils and the LD50 of it. A study conducted with various caffeine levels (10, 20, 40, 60 mg/kg) showed little influence on the operant behavior of gerbils. It was suspected that caffeine reduces the appetite of gerbils.

LD50 of caffeine

For dogs, the LD50 of caffeine has been determined to be 140 mg/kg (source). Humans have a little higher LD50 which ranges between 150 and 200 mg/kg. A study also has determined the LD50 of caffeine in albino rats. This study established an LD50 of 367 mg/kg.

For gerbils, this LD50 hasn’t been determined. Even if gerbils would have a (high) LD50 of caffeine similar to that of rats, only small amounts of chocolate could be tolerated. Let’s take the previously mentioned weight of 60 g for an average adult gerbil. In such a case, the gerbil would ingest the median lethal dose at 22 mg of caffeine (55 g of milk chocolate or 30 g of the dark chocolate).


Animals usually lose the enzymes that are required to digest milk after weaning. Most adult animals don’t consume milk and are lactose intolerant, which means they can’t properly digest milk (products).

Not all chocolate contains lactose. Below you can find the lactose content of chocolate:

  • dark chocolate (75% cacao): 0 to 0,5 g per 100 g
  • milk chocolate: 9,5 g per 100 g

Chocolate Toxicity

There are no studies online that researched the lethal dose of theobromine and caffeine in gerbils. It’s difficult to determine the health issues that gerbils can get when ingesting chocolate but similarities can be expected with the signs of theobromine toxicity in other (small) pets.

Symptoms of chocolate toxicity (depending on dose)

  • hyperactivity
  • drooling
  • diarrhea
  • high heart rate
  • high blood pressure
  • irregular heartbeat
  • tremors
  • seizures

If the level of theobromine (and caffeine) is high enough or if there are complications from the other health issues it can cause, death can follow.

What To Do When Your Gerbils Ate Chocolate?

When your gerbil has eaten chocolate it’s important to seek the help and advice of a vet. Since I’m no vet I can’t give any further advice.

The treatment (for dogs) usually consists of treating the symptoms with medication and stabilizing the pet. It’s also key to get the theobromine and caffeine out of their system as soon as possible. With dogs, this is partially done by letting the dog vomit but gerbils can’t vomit so this isn’t an option.

If you haven’t already done so, find a vet in your neighborhood that’s specialized in gerbils and write down their number. Put it down on a piece of paper and keep it close for emergencies. Also, locate the nearest pet hospital and do the same.

If you live in the USA you can find emergency vets and pet hospitals on and

What Treats Are Safe for Gerbils?

So, gerbils shouldn’t be fed chocolate but what can they eat? There are a lot of safe and healthy treats available for gerbils:

  • seeds
  • nuts
  • fruit
  • vegetables
  • plants & herbs
  • mealworms
  • crickets
  • scrambled or boiled eggs
  • unsweetened breakfast cereal

If you want to give ready-to-go snacks to your gerbils I would recommend the following snacks:

Want to Learn More?

If you’re interested in learning more about gerbils as pets, please read the following articles:

If you’re interested in getting gerbils as pets, you should read our beginner’s guide to keeping gerbils as pets and our gerbil care guide.

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