Guinea pigs should never eat onions, garlic, chives, leeks, chocolate, avocado, rhubarb, caffeine, dairy, meat, or sugary and salty human snacks. These foods can cause serious digestive trouble, poisoning, or long-term health problems in an animal with a very sensitive gut.
Foods to Never Feed a Guinea Pig
- Onions, garlic, leeks, chives and shallots. This whole plant family can damage red blood cells and upset the gut.
- Chocolate, coffee, tea and other caffeine. They contain stimulants guinea pigs cannot handle. See our post on guinea pigs and chocolate.
- Avocado. The flesh, skin and pit contain persin and a lot of fat; avoid all of it.
- Rhubarb. The leaves are high in oxalates and are considered poisonous.
- Meat, eggs, fish and dairy. Guinea pigs are strict plant eaters and cannot digest animal products.
- Nuts, seeds, and seed-heavy treat sticks. They are high in fat and can be a choking risk.
- Bread, crackers, chips, cereal, cookies and candy. These are starchy, sugary or salty and offer nothing useful. See crackers.
- Raw or green potatoes and potato skins. They contain solanine and are hard to digest.
- Tomato leaves and stems. The ripe fruit is fine in small amounts, but the green parts are not. More in our tomato guide.
- Mushrooms and dried beans. They are hard to digest and some wild mushrooms are poisonous.
Foods to Limit, Not Ban
Some foods are not poisonous but cause trouble in large amounts. Fruit is high in sugar, so keep it to a small treat a few times a week. Calcium-rich greens such as spinach, kale and parsley are best rotated rather than fed daily, because too much calcium can contribute to bladder stones. Iceberg lettuce is mostly water with little nutrition, so choose darker lettuces instead.
Poisonous Houseplants and Garden Plants
Do not let your guinea pig nibble on houseplants or garden flowers unless you are sure they are safe. Lilies, daffodils, tulips, foxglove, ivy and many bulbs are toxic. Never feed grass or weeds that may have been treated with pesticides or fertilizer. Our guide to feeding grass safely explains how to do it right.
What to Feed Instead
The bulk of the diet should be unlimited grass hay, a small portion of plain timothy-based pellets with added vitamin C, and a daily cup of fresh vegetables such as romaine, bell pepper and cilantro. For the full list, see what you can feed guinea pigs and our best food guide.
What to Do If Your Guinea Pig Ate Something Bad
Remove any remaining food, note what and how much was eaten, and call your veterinarian or an animal poison hotline right away. Do not wait for symptoms, and do not give any medicine at home. Warning signs include drooling, not eating, a bloated belly, diarrhea, lethargy or hiding.
Bottom Line
When in doubt, leave it out. Stick to hay, guinea pig pellets and safe fresh vegetables, and check any new food before offering it.
This article is for general information and is not a substitute for veterinary advice. If your guinea pig seems unwell, contact an exotic-pet veterinarian.
