Everyone knows that guinea pigs love to eat. However, there are many foods that guinea pigs simply can’t eat without serious consequences.
The following list of foods can cause an upset stomach or worse if guinea pigs were to eat them.
Some of these are extremely toxic, while others will cause varying degrees of digestive issues or long-term health problems if fed over time.
I’ll start with the most dangerous foods at the top of the list and gradually work down to the foods that are not toxic but best avoided.
You can also find a chart of all the foods guinea pigs can eat along with the frequency it can be given on the guinea pig food chart page.
Meat is one of the biggest ones on this list to avoid feeding your guinea pig. Guinea pigs are strict vegans and cannot digest meat at all.
Eating even small amounts of meat can make them very sick. This includes any kind of meat or fish, cooked or raw.
2. Dog or Cat Food
Since guinea pigs can’t eat meat, this also disqualifies any kind of kibble, treats, or other foods you would feed to your cat, dog, or ferret.
If your guinea pig free roams for floor time, make sure they do not have access to any food bowls of other pets.
As mentioned above, guinea pigs are strict vegans. Dairy of any kind is very bad for your guinea pigs and cannot be digested properly.
This includes milk, yogurt, cheese, ice cream, sour cream, cream cheese, whipped cream, etc.
Consuming any of these can cause stomach aches or make your piggy ill.
4. Animal By-Products
Besides meat and dairy, guinea pigs should stay away from all other kinds of animal by-products as well. This includes eggs, honey, mealworms, and anything that includes gelatin or other animal-derived ingredients. Guinea pigs are not designed to digest any kind of food that comes from an animal. Honey is also far too sticky and high in sugar.
5. Chocolate or Candy
At best, chocolate and candy of any kind are very unhealthy for your guinea pig. Certain kinds can also be very toxic. For these reasons, chocolate and candy should be avoided completely. Any kind of food with lots of sugar can have harmful effects on guinea pigs.
Garlic is poisonous to guinea pigs and will cause bad stomach pains for your piggy.
They contain a compound that damages red blood cells and can cause severe breathing problems and weakness in guinea pigs.
Small amounts can cause a lot of discomfort for your piggy and can elicit toxic effects. For these reasons, it’s important to keep garlic far away from your guinea pig.
Anything from the onion family, including onions, spring onions, onion grass, leeks, chives, and shallots, should never be fed to guinea pigs. Similar to garlic, they are very toxic and damage the guinea pig’s red blood cells. Be sure to keep them strictly off your guinea pig’s menu.
Potatoes are toxic and should not be fed to guinea pigs. Potato tops and leaves are also poisonous.
Green potatoes are even more dangerous for guinea pigs because they contain large amounts of solanine, which is very poisonous to piggies.
Potatoes also have high levels of carbohydrates, so they’re not healthy for guinea pigs from a nutritional perspective either.
9. Rotten or Moldy Food
This one may seem obvious, but it’s an important reminder to double-check any food before feeding it to your guinea pig.
Turn any vegetables over in your hand to check for little mold spots before giving them to your guinea pig. Sometimes these little spots can be easy to miss!
Also, remove any uneaten vegetables from your guinea pig’s cage after a few hours. Make sure nothing has become buried in bedding, as this quickly leads to moldy food in the cage.
Also, check hay for mold when you first buy it and periodically before feeding it to your pigs. Hay that has been exposed to moisture can start growing mold quickly. Usually, mold in hay is easy to detect by smell.
This is also an obvious but important one that should no doubt be avoided with guinea pigs. Alcohol can burn the throat and make your piggy very ill.
Guinea pigs should not have anything that contains caffeine. Beans are also not good for guinea pigs and can cause serious stomach problems.
As mentioned above, guinea pigs should not consume any kind of caffeine. Tea may also contain herbs that are not safe for guinea pigs.
13. Plants or Veggies With Pesticides
Beware of pesticide or herbicide-treated plants if you collect grass or dandelions for your guinea pigs outside. Guinea pigs are very sensitive to chemicals like this and can get very sick if exposed to them.
It can be hard to tell if plants have been treated, but if in doubt, avoid feeding them to your guinea pig.
As a general rule, avoid picking grass from neighbors’ yards unless you’ve talked to them first. Parks, public walkways, and boulevards can also be risky.
Grass in public areas may have been soiled by other animals or exposed to exhaust fumes from cars driving by.
Try to stick to grass on your own property if possible, and avoid picking anything too close to sidewalks or property lines where other people may have treated grass nearby.
Also, be aware that most non-organic vegetables from the grocery store contain subtle traces of pesticides. This is less dangerous than most weed-killer pesticides you’ll find outside, but they can still be hazardous to your guinea pig. This is why it’s important to thoroughly wash vegetables before feeding them to your piggies.
Did you know?
Untreated grass is healthy and great for grinding down your guinea pig’s molars. It is one of a few foods that can be safely fed to your piggies daily. This makes it a great option to feed your guinea pigs if you run out of food for your piggy temporarily.
For a list of more healthy staples, check out this list of 10 foods you can feed your guinea pig daily.
14. Lawnmower Clippings
Lawnmower clippings can also be potentially dangerous for your guinea pig. Grass clippings can cause serious digestive upsets and can make your guinea pigs very ill.
This is because lawnmower fuel gets mixed in with the grass clippings. The chemical residue on the grass is quite toxic to guinea pigs and can cause bloat and other gastrointestinal issues.
You also may have poisonous weeds around your yard that could easily get mixed in together with the grass clippings. This can cause a whole host of other problems if your guinea pig eats them.
To avoid any problems with grass clippings, avoid feeding them to your guinea pig altogether. Always hand pick the grass that you feed to your guinea pigs. Also, be sure to rake up any lawnmower clippings before taking your guinea pigs out to play in the grass.
15. Glue, Paint, Varnish
Be careful about your guinea pigs chewing things that are coated with non-food grade paint or varnish. These have chemicals that could be harmful to your guinea pig. Anything with industrial-type glue or tape can be toxic as well.
Pickles and any other type of pickled foods should not be fed to your guinea pig. They are very acidic and also quite high in sodium. Because of this, pickles can cause severe stomach upset and pain for your guinea pig. Even small amounts should not be fed to guinea pigs. However, it’s perfectly safe to feed your guinea pig fresh, raw cucumbers as a nice snack instead.
17. House Plants and Other Garden Plants
Many house plants and even flowers outside in your garden can be quite dangerous to guinea pigs.
Some examples of known poisonous plants for guinea pigs include clematis, columbine, nightshade, dog mercury, fool’s parsley, poppies, honeysuckle, yew, ragwort, foxglove, horsetails, hemlock, ivy, lobelia, sorrel, lupins, and many more.
Buttercup flowers (yellow wildflowers) and daisies (yellow and white wildflowers) are also poisonous to guinea pigs. Be careful not to collect any of these wildflowers or their leaves and stems if you collect grass for your guinea pigs outside.
This is not a complete list, however, and countless more plants are considered poisonous or potentially poisonous to guinea pigs. Some plants, such as hostas or ferns, have little information known about them with regard to guinea pigs.
However, since they are poisonous to many other animals, it’s safe to assume they’re poisonous to guinea pigs too.
Unless you’ve learned that a specific plant is safe for guinea pigs, it’s best to err on the side of caution and assume that any plant in your home or garden is poisonous to your guinea pig.
A few flowers that guinea pigs can eat include dandelions, marigolds, roses, and chamomiles. Guinea pigs often love these plants, fresh or dried, and they have great health benefits for guinea pigs.
18. Oak and Maple Trees
Maple leaves contain gallic acid, a compound that is very dangerous to guinea pigs.
Both fresh and dried maple leaves are very toxic and should never be fed to your guinea pig.
All parts of the oak tree are also poisonous to guinea pigs and many other herbivorous animals. Some oak species are more toxic than others.
However, it’s always better to be on the safe side. Do not let your guinea pig eat any oak leaves, flowers, acorns, or branches.
19. Jalapeno Peppers
Hot peppers and any other kind of hot, spicy foods should not be fed to your guinea pig. These can cause pain, stomach upset, and other problems for your guinea pig’s sensitive digestive system.
20. Eggplant Leaves or Unripe Eggplants
Eggplant leaves have a high amount of solanine, which is highly toxic to guinea pigs.
Unripe eggplants that have green anywhere on the outside or inside of the fruit also contain this toxin. As such, you should never feed your guinea pig an unripe eggplant.
However, fully ripe eggplants without leaves are safe for guinea pigs. They don’t have much nutritional value, but some guinea pigs really like them as an occasional treat.
21. Plants That Grow From a Bulb
Most plants that grow from a bulb are very dangerous for guinea pigs if consumed. This includes daffodils, lilies, tulips, hyacinths, iris, lily of the valley, anemones, bluebells, snowdrops, and more.
If in doubt, avoid feeding them to your guinea pig! Also, make sure your guinea pigs don’t have access to unknown plants in or outside of a garden if you ever take them outside to graze.
22. Evergreen Trees and Shrubs
Most coniferous trees (anything with pine needles) are poisonous to guinea pigs. Don’t let your guinea pig chew on Christmas trees in the house, and avoid letting them graze near any kind of shrubs or pine trees if you take them outside.
23. Tomato Leaves and Stalks
Tomato leaves and stalks are very poisonous to guinea pigs. Also, avoid feeding your guinea pig any green tomatoes that are not yet ripe. Unripe tomatoes also contain traces of this poisonous compound.
Fully ripe tomatoes are safe and healthy for guinea pigs, but make sure you remove any greenery before feeding them to your piggies!
Related: 21 Low Calcium Foods for Guinea Pigs
Rhubarb leaves and stalks are both poisonous to guinea pigs and could make them very sick. Even if this was not the case, rhubarb is also very high in oxalic acids and could cause kidney and urinary tract stones to develop.
25. Avocado Skin, Pit, and Seeds
The skin of an avocado, as well as the pit and seeds, are poisonous to guinea pigs. The inside flesh of the avocado is safe for them to eat, but it is still very high in fat.
For this reason, it’s best to avoid feeding your guinea pig any avocado. Many guinea pigs struggle with obesity to begin with, so adding even more fat to their diet can quickly spiral into other problems.
26. Plastic Bags and Other Objects
While plastic is not edible, many guinea pigs seem to think it is! I’ve had countless guinea pigs try to eat plastic. Plastic bags, plastic toys, even laundry baskets!
Eating plastic is not great for your guinea pigs. Not only is it completely indigestible, but the edges of plastic can be sharp. In addition, bigger pieces of plastic can sometimes cause blockages in your guinea pig’s intestines.
Be sure to supervise your guinea pig when they are out of the cage to ensure they don’t eat anything they shouldn’t. Also, try to proactively piggy-proof your floor time space before letting them out to roam and explore. Guinea pigs are like nibbly toddlers that never grow up. Anything they can chew or eat will likely end up in their mouth!
27. Rabbit or Hamster Food
Even though guinea pig food may look similar to rabbit or hamster food, the ingredients are vastly different! The same goes for gerbil, mouse, rat food, etc. Guinea pigs have very different nutrient requirements than these other animals, and they need food that meets these specific requirements.
One of the main things that guinea pig food has is added vitamin C. Guinea pigs cannot make their own vitamin C and therefore need this included in their diet. Guinea pigs that are deficient in vitamin C develop a condition called scurvy, a dangerous disease that causes severe pain and joint problems.
In addition, hamster food often contains corn or small seeds that can be a choking hazard for guinea pigs.
Rabbit food is also too high in Vitamin D for guinea pigs and sometimes contains drugs to prevent coccidiosis, which can be harmful to guinea pigs.
When choosing an appropriate food for your guinea pigs, choose a high-quality pellet without colored pieces or seeds.
These colored pieces are flavored and colored for more visual appeal, but they are not healthy for your guinea pig.
These foods also encourage your guinea pig to pick out the flavored parts of the food, meaning they are consuming empty calories and leaving the healthiest part of the pellets.
Oxbow’s brand of guinea pig food is most often recommended by vets and pet owners alike. That’s also what I’ve fed my own piggies for the last 10 or so years to keep them healthy and active.
Wild mushrooms should never be fed to guinea pigs because many types are poisonous. Most mushrooms from grocery stores are safe for guinea pigs, but they don’t contain much nutritional value for guinea pigs. Therefore, it’s best to skip this food and choose healthier options for your piggy instead.
Recommended: 15 Foods For Guinea Pigs That Are High in Vitamin C
With the exception of green beans, most varieties of beans and lentils should not be fed to guinea pigs.
Dried beans can be hazardous to your guinea pig as they pose a choking risk. Guinea pigs should also not eat any kind of cooked or canned food in general.
Many types of beans have too much water content and are high in phosphorus, calcium, and other things that can cause stones or other problems in guinea pigs.
Additionally, beans can often cause indigestion and bloat. Certain types of beans, such as runner beans, are also poisonous to guinea pigs.
30. Processed Human Foods
Any kind of man-made food is unhealthy and should not be fed to guinea pigs. They are not able to digest the same types of food that we can. Because of this, many processed foods can cause stomach aches in your guinea pig.
Common human foods you should never feed your guinea pig include french fries, potato chips, pizza, toast, pasta, cookies, biscuits, and crackers.
Ginger is not good to give to guinea pigs due to its high calcium and sugar content. Raw ginger can also cause painful digestive upsets for your guinea pig.
Pickled ginger is also hard on your guinea pig’s digestive system and shouldn’t be fed to your piggy.
Popcorn is not poisonous to guinea pigs, but it is very high in calories and fat. Popcorn is also dry and poses a choking risk for your guinea pig. Raw corn kernels can be even more dangerous for choking. Because of this, it’s best to avoid feeding your guinea pigs popcorn.
Guinea pigs also have difficulty digesting processed human foods, such as popcorn. Popcorn also has no real health benefits for guinea pigs, and the high-calorie content can cause countless problems.
33. Peanut Butter
Peanut butter is very high in fat and calories. It’s also a very sticky substance that guinea pigs can easily choke on or get stuck in their teeth.
In addition, guinea pigs find it hard to digest things like nuts, and it may give them stomach trouble. For all these reasons, peanut butter should not be fed to your guinea pig.
34. Alfalfa Hay
Alfalfa (also known as Lucerne) is a form of legume hay. Alfalfa hay is fairly high in calcium, which can cause bladder stones over time. Fresh alfalfa grass is even richer in calcium.
Because of the high calcium levels, alfalfa should not be fed to adult guinea pigs. It’s fine to feed fresh or dried alfalfa in reasonable amounts to growing guinea pigs under 6 months only, but it is not a necessity. Baby guinea pigs will grow perfectly well with other sources of calcium, such as by feeding higher calcium vegetables and greens.
Alfalfa hay is often genetically modified to grow more efficiently and be resistant to weed killers. Non-GMO crops are a healthier alternative where possible, so grass hays like timothy or orchard hay are preferable for your piggies. Check out this article on the best types of hay to feed your guinea pig for more information.
35. Dried Fruit
Dried fruit isn’t toxic to guinea pigs, but it tends to have a higher amount of sugar and preservatives than fresh fruit.
In addition, they don’t have much nutritional value, and the sticky fruits can get stuck in your guinea pig’s teeth.
Even fresh fruit can be pretty high in sugar and is best fed to guinea pigs occasionally.
If you want to feed your guinea pigs any dried fruit such as raisins, dates, figs, prunes, or dried apricots, do so in very small amounts as a rare treat only.
36. Cereals, Bread, and Other Grains
Guinea pigs don’t have a digestive system that is well built to digest grains. In addition, human foods that are grain-based generally have sugar and preservatives added that are not good for guinea pigs. Many grain-based foods are also high in fat and carbohydrates, which can quickly contribute to weight gain in guinea pigs.
Some grains like bread can also be quite dry and easy for guinea pigs to choke on. In most cases, it’s best to avoid grains entirely for your guinea pig. This includes any type of bread, buns, breakfast cereal, rice, oats, and countless others.
37. Cooked Food or Vegetables
Guinea pigs have evolved to eat raw vegetables and forage. Their digestive systems struggle with any kind of cooked food.
In addition, cooked food tends to have a lower nutritional value than raw. Soft cooked foods also do nothing to help wear down your guinea pig’s constantly ever-growing teeth.
38. Canned Vegetables and Fruit
While a small amount is not likely to seriously harm your guinea pigs, canned vegetables tend to have added preservatives and salt, which is not great for guinea pigs.
Some of the nutrients in canned food are also depleted in order to make it shelf stable. Feeding fresh fruits and veggies to your guinea pigs is a much healthier option.
39. Frozen Fruit or Vegetables
Frozen vegetables and fruit are also unlikely to harm your guinea pig, but fresh food is a much healthier alternative. In some cases, frozen foods can cause a digestive upset.
In addition, store-bought frozen veggies are often blanched first before they are frozen.
Blanching involves partially cooking the vegetables, which removes some of the nutrients that would normally be found in the raw form of the foods.
Also, many veggies that are healthiest for guinea pigs, such as leafy greens, do not freeze well. They thaw out in a rather wilted, soggy form that most guinea pigs would refuse to eat anyway.
Freezing sometimes changes the taste, texture, and water content of vegetables as well. Most guinea pigs much prefer the taste of raw, natural veggies.
While not inherently dangerous, coconut is very high in fat. It also has high levels of phosphorus, which can contribute to the formation of stones in guinea pigs.
Coconut is not a natural part of a guinea pig’s diet, and it doesn’t contain any important nutrients that guinea pigs would normally need in their diet. For these reasons, coconut is best not fed to guinea pigs.
41. Guinea Pig Treats Containing Honey, Seeds, Yogurt
Despite being marketed towards guinea pigs, many guinea pig treats are simply not safe to feed your guinea pigs. This includes yogurt drops, chew sticks that are made of seeds and honey, or other sugary types of treats.
Yogurt drop treats are frequently sold in pet stores and marketed toward guinea pigs. Small pieces may not seriously harm your guinea pigs, but they can cause an upset stomach and long-term problems due to the high sugar content and traces of dairy.
Many dried fruit-type treats are also very high in sugar and have absolutely no nutritional value. Anything with seeds or honey should be avoided, as they are very unhealthy and also pose a choking hazard.
42. Lemons and Lime
Certain citrus fruits, such as lemons and lime, are quite acidic for guinea pigs and should generally be avoided. The high levels of acidity can cause mouth sores, teeth issues, and digestive problems for your guinea pig.
Other types of citrus can be fed to guinea pigs but in small amounts only, as too much acidity can lead to stomach pains and other issues.
However, many types of citrus contain a wealth of nutrients and can be beneficial for your guinea pig as an occasional treat.
For example, oranges have high levels of Vitamin C, which is great for guinea pigs. They’re also slightly less acidic than other citrus fruits.
However, all citrus has higher levels of sugar and acidity, so even oranges should be fed in small amounts.
Also, remember to remove the orange seeds first, as they can present a choking hazard to your guinea pig.
Orange peels are also safe for guinea pigs to eat. They actually contain even more Vitamin C than the oranges themselves! Just like oranges, they should be fed in small quantities due to their acidity.
It’s also best to only feed your guinea pigs orange peels from organic oranges. Orange peels are often laced with pesticides that can be hard to wash away completely.
Any kind of nuts, including peanuts, almonds, cashews, walnuts, pistachios, hazelnuts, pecans, and others, are far too high in fat for guinea pigs to eat.
They can also be a choking hazard. Guinea pigs are not built to digest these types of foods, so eating them can cause pain and stomach aches for your guinea pig.
44. Many Types of Seeds
Most seeds should be avoided with guinea pigs. Seeds can be a choking hazard, and some can get stuck in your guinea pig’s teeth. Many seeds are also high in fat, which most guinea pigs don’t need in high quantities. Additionally, apple seeds contain arsenic, a compound that can be very dangerous to guinea pigs.
The only seeds that guinea pigs can safely eat are small seeds found in certain vegetables such as bell peppers, tomatoes, and cucumbers. These seeds are small and soft enough that they don’t pose a problem.
45. Iceberg Lettuce
While not inherently dangerous to guinea pigs, iceberg lettuce can cause diarrhea and an upset stomach. This watery vegetable also contains next to no nutritional value for your guinea pig. All in all, it’s best kept off your guinea pig’s menu.
There are so many healthier vegetables you can feed your guinea pig instead. Some good alternatives are bell peppers, kale, or other leafy green varieties of lettuce that have a higher nutritional value.
While not poisonous to guinea pigs, this sweet herb is extremely high in calcium. Oregano contains 1600mg of calcium per 100 grams. In comparison, romaine lettuce has about 35mg of calcium per 100 grams. As you can see, oregano is incredibly calcium-rich over other common fruits and vegetables that you would feed your guinea pig.
Over time, the high calcium content can contribute to bladder stone development in guinea pigs, which can be very painful and life-threatening. For this reason, it’s crucial to cut-out or minimize any oregano in your guinea pig’s diet.
The best diet for your guinea pig consists of free access to grass hay, small amounts of high-quality pellets, and a variety of healthy and safe vegetables.
As you can see from this list, many foods are unsafe or best excluded from your guinea pig’s menu. Some of the things on this list are common knowledge, but many can take you by surprise.
As you venture into guinea pig ownership, you will likely find countless products that are unsuitable for guinea pigs. Many things are even sold in pet stores and advertised directly to guinea pig owners.
To find a list of products you should avoid buying for your guinea pig, check out this list of 15 things you should never buy for your guinea pig.
You may also be wondering what fruits, vegetables, and herbs and safe and healthy for guinea pigs. For a comprehensive list of foods you can feed your guinea pig, check out our guinea pig safe foods list.