Lesley is an artist and the author of a guinea pig care guide.Guinea pigs can eat carrots, among many other fresh veggies.These suggestions for different foods, kibble, and hay are based on my own experiences.Different guinea pigs have different preferences, but generally, they love to sample a variety of different fruits and veggies.Carrots, peppers, and dark lettuces are a surefire hit with my guinea pigs.If you encounter a picky eater who won't eat fresh produce, ask your veterinarian about different types of Vitamin C-fortified pellets to make sure your little friend gets the right nourishment.Here is a list of just some of the many fruits and vegetables that guinea pigs eat and that give them the best nutritional benefits.Also, avoid any sudden major changes in your pet's diet until you know how their tummy reacts to things.Carrots: Both the roots and green tops are perfectly safe to eat.Both the roots and green tops are perfectly safe to eat.Feed spinach a bit sparingly to avoid potential kidney problems.Feed spinach a bit sparingly to avoid potential kidney problems.Parsley: Guinea pigs love either curly or flat parley, and it smells delicious when you're tearing sprigs off the bunch!While guinea pigs do enjoy a variety of flavors and types of fruits and vegetables, there are some that you shouldn't offer.They are not all poisonous, but they should be avoided because they're either low in nutrients or produce gas and other tummy troubles.Iceberg lettuce: It won't kill your guinea pig if you give him or her a little piece, but it has virtually no nutritional value, and it is quite fibrous and watery.With the great selection of other more leafy, dark lettuces available, just avoid this one and go with one of the others.It won't kill your guinea pig if you give him or her a little piece, but it has virtually no nutritional value, and it is quite fibrous and watery.With the great selection of other more leafy, dark lettuces available, just avoid this one and go with one of the others.Any type of cabbage: Like iceberg lettuce, a small piece is not likely to severely harm or kill your guinea pig, but it's very gassy and not good for their little systems.Like iceberg lettuce, a small piece is not likely to severely harm or kill your guinea pig, but it's very gassy and not good for their little systems.Toxins can exist in potato skins, particularly if they've begun to turn green, and can be poisonous.While many stores will offer yogurt drops and other "treats," dairy is not healthy for guinea pigs and can actually cause problems.In addition to Western timothy hay, there are other varieties with different nutritional properties, textures, and flavors.Guinea pigs will eat hay nonstop, but you don't have to worry because it will not make them fat.No amount of hay will put weight on a piggie because it's not actually fully digested into their body.Sometimes when I go to the pet store, I find bags of timothy hay that look more like straw.It pays to find a nice, fresh, green bag of hay.I discovered it online and then found that my vet used it, too, so it's definitely the cream of the guinea pig crop!It's completely possible to sustain your guinea pig solely on fruits, vegetables, and hay, but you want to make sure that you're feeding them enough vitamins and minerals.If you are thinking of skipping pellets altogether, speak with your vet about it first.Assuming that you go the more traditional route of combining pellets with fresh vegetables and hay, here's what you need to know:.Even though there are "treats" marketed to guinea pigs on the shelves of pet stores, it's best not to buy them.Even if a bag of pellets says that it's fortified with Vitamin C, do not take this as a replacement for vitamin-rich vegetables.Guinea pigs cannot eat hamster, rabbit, or gerbil food.My guinea pigs seem to like the taste the best, and this formula has a special type of Vitamin C that is meant to last a long time.You could technically omit the other vitamin supplements in vegetables and the guinea pigs would be fine.Unlike hay, too many pellets will make your guinea pig overweight.If you notice your guinea pig gaining weight, there are a number of things you can do to make sure it doesn't get out of hand, while still keeping them satisfied.This is a wonderful thing because guinea pigs, like humans, are one of the few species of animal whose bodies aren't able to generate Vitamin C