Foods toxic to guinea pigs
Every food we've flagged as unsafe for guinea pigs — with the reason, and a cited source for each.
🚨 If your guinea pig already ate something on this list
Don't wait for symptoms. Call your vet, or ASPCA Animal Poison Control (888) 426-4435 / Pet Poison Helpline (855) 764-7661.
Never feed these to guinea pigs (17)
These are unsafe at any amount, or dangerous enough that they're not worth the risk.
Why each one is a problem
Avocado. Contains persin, which can damage the heart, and is too fatty; all parts are dangerous. Full details →
Bread. A processed, starchy human food with no place in a herbivore's diet. Full details →
Chives & leeks. Alliums like onion and garlic that can cause dangerous red blood cell damage. Full details →
Chocolate. Contains theobromine and caffeine that cause heart and nervous-system problems and can be fatal. Full details →
Corn. Kernels are high in starch and sugar and are not recommended for guinea pigs. Full details →
Dairy. Guinea pigs are herbivores that cannot digest dairy, so never feed cheese, milk or yogurt. Full details →
Garlic. An allium containing sulphur compounds that destroy red blood cells; never feed it. Full details →
Grass clippings. Lawnmower clippings ferment quickly and cause serious digestive upset; never feed them. Full details →
Iceberg lettuce. Offers little nutrition and its high water content can cause diarrhoea, so avoid it. Full details →
Meat. Guinea pigs are strict herbivores and cannot digest meat or other animal protein. Full details →
Mushrooms. Not suitable for guinea pigs and some varieties are toxic, so avoid them. Full details →
Nuts. Too high in fat and a choking hazard; not suitable for guinea pigs. Full details →
Onion. An allium that damages red blood cells and can be fatal, so never feed it. Full details →
Peas. High in starch and sugar and not recommended; can contribute to digestive and dental problems. Full details →
Potato. Contains solanine, especially in green parts and skin, which is toxic to guinea pigs. Full details →
Rhubarb. High oxalic acid is toxic and can cause bladder stones; the leaves are especially dangerous. Full details →
Seeds. High in fat and a choking hazard, so never feed loose seeds. Full details →
Safe only in moderation (20)
Not toxic, but these should be occasional or small-portion foods for guinea pigs — the reason is on each page.
What guinea pigs should actually be eating
For guinea pigs, unlimited grass hay is the foundation, plus daily leafy greens — and they must get vitamin C from food every day. Treats stay small.
Frequently asked questions
What foods are toxic to guinea pigs?
The most common unsafe foods for guinea pigs include avocado, bread, chives & leeks, chocolate, corn, dairy. Each is listed below with the reason why.
What should I do if my guinea pig ate something toxic?
Contact your vet or a pet poison line immediately — ASPCA Animal Poison Control (888) 426-4435 or Pet Poison Helpline (855) 764-7661. Don't wait for symptoms to appear.
How much of a toxic food is dangerous for guinea pigs?
It varies by food and by the size of the animal — some are dangerous in tiny amounts. Treat any amount as worth a call to your vet.
See the full list of what guinea pigs can and can't eat →