You enjoy giving your guinea pig vegetables for treats, though never more than 10% of their overall diet. However, there are several vegetables you should never give guinea pigs. The reason varies from poison to long term health problems. Since you want your piggle to live a long and healthy life, keeping this list around is a good idea.
Broccoli & Cauliflower
Broccoli, cauliflower, and anything else in that family are among the vegetables you should never give guinea pigs. The issue with these vegetables is that they create gas in your guinea pig’s intestines. Your guinea pig may be able to pass a small amount safely. However, and large amounts can cause bloat. In rare cases, this may even require vet treatment.
Light Lettuces
You should never give guinea pigs these lettuces. The light color indicates higher water content. This water alone can cause your guinea pig’s digestive tract issues. However, these lettuces also offer your guinea pig no nutritional value. The resulting problems simply are not worth the treat.
Light lettuces include iceberg, cabbage, and bok choy.
Corn
Corn is a weird vegetable since humans can’t digest it either. The canned varieties would put too much salt in your guinea pig. Meanwhile, guinea pigs can’t digest cooked foods. While corn may sound like a good idea and be popular in many treats, it does nothing for the guinea pig nutritionally.

Onions, Chives, & Shallots
Onions, chives, and shallots all originated in Eurasia. Since they were not part of the guinea pig diet while the species was evolving, guinea pig systems cannot handle these plants. Feeding them to your guinea pig, especially in quantity, can trigger blood disorders. These disorders take commitment to treat, so you should never feed these vegetables to your guinea pig.
Garlic
Garlic is prevalent in many cuisines, and chances are you have it around the house. However, you should never feed this vegetable to your guinea pig. Unfortunately, it’s poisonous to your little piggle on top of not being digestible. If your guinea pig gets ahold of garlic, proceed to your local veterinarian at once.
Mushrooms
Mushrooms are a complex topic, given there are many different types out there. Some are harmless but offer your guinea pig no nutritional value. Others are poisonous to them or may cause vitamin and mineral excesses. The latter is what earns it a spot on the Guinea Pig Center list of vegetables you should never feed your guinea pig.

Potatoes
Potatoes are one of the vegetables you may think is all right to feed guinea pigs since they both originate from the Andes region. However, potatoes developed a defense mechanism against being eaten a long time ago. This alkaloid makes the potato toxic to most mammals. Humans can eat potatoes because we cook it, but guinea pigs can’t digest cooked food. That’s why potatoes make the list of vegetables never to feed your guinea pig.
Rhubarb
Rhubarb is an unusual plant. To prevent consumption, it produces a high concentration of oxalic acid. Humans use oxalic acid for a variety of commercial purposes, from laundry to antifreeze, in addition to consumption. Guinea pigs don’t have that choice. Instead, the acid gathers in their urinary tract, where it can form harmful deposits.
Tomato Stalks & Leaves
While tomatoes may be a fruit, the rest of the plant often gets treated like a vegetable. Unfortunately, you can’t feed out tomato stalks and leaves to a guinea pig. These items are poisonous to the guinea pig. However, feeding the fruit in small quantities poses no danger.