What Guinea Pigs Can and Cannot Eat

Guinea pigs have unique digestive systems that require a constant supply of fiber to help them digest their food and prevent impactions.

Their stomachs go through a double digestion process wherein they eat once, digest their food, create soft fecal matter in a pouch in their rump, eat those, and digest it again. I know that sounds gross, but this is an important part of your piggie's health.

Hay is a staple in a guinea pig's diet. You can honestly never have too much hay. When guinea pigs are babies, they can have some alfalfa hay, which has a different balance of nutrients than the timothy hay that adult guinea pigs eat, but by the time they're full-grown guinea pigs, they should have only timothy hay- and lots of it!

You can find western timothy hay in most pet stores, but you want to make sure that you find a bag that looks nice and fresh. 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. Your piggie will be so happy!

A great brand to go for is Oxbow. I discovered it online and then found that my vet used it, too, so it's definitely the cream of the guinea pig crop! Some of their products are carried in pet stores, and your vet may also carry these supplies, but it's very simple and affordable to order right through a website like Amazon. I found some of the products and have listed them below for you!

Guinea pigs will eat it 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, it's used by their digestive system to "move things along".

It's completely possible to sustain your guinea pig solely on fruits and vegetables and hay, and skip the pellets altogether. But you want to make sure that you're feeding them enough of what they need as far as vitamins and minerals, and it's highly advisable not to do this unless you talk to your veterinarian first.

Assuming that you go the more traditional route of pellets combined with fresh vegetables and hay, here's what you need to know:

Never feed a guinea pig anything with seeds. Even though there are 'treats' marketed to guinea pigs on the shelves of pet stores, NEVER buy them! These are unnecessary to a pig's diet and guinea pigs are prone to choking, so if it looks like birdseed or hamster food, STAY AWAY.

Most pet stores will carry a variety of brands. 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. We will cover vitamin C in the next sections.

Guinea pigs cannot eat hamster food, rabbit food, gerbil food, etc. You wouldn't pour a can of dog food on your plate for dinner, even if it looks similar to your mom's pot roast, so why would it make sense to give a guinea pig rabbit food just because the pellets look the same? You should never feed your guinea pig any food that's labeled for the nutritional balance of another animal.

The best brand of pellets I've found so far is once again the Oxbow brand. My guinea pigs seem to like the taste the best, and this formula has a special type of vitamin C that is truthfully meant to last a long time. My veterinarian has said in this case with the Oxbow brand, you could technically omit the other vitamin supplements in vegetables and the guinea pigs would be fine. But you want to feed them those anyway because they love them so much!

In contrast to hay, too many pellets will make your guinea pig overweight. So, just be sure that you ration the amount you give them to a handful or two a day depending on the size of your guinea pig. If you notice your guinea pig gaining weight, it's good to check with your vet to find out what you can do to make sure it doesn't get out of hand while still being able to keep your guinea pig from going hungry.

We've established that guinea pigs love fruits and veggies. 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.

If we or guinea pigs don't get enough vitamin C in our diets, we can contract a condition known as scurvy. This can make a guinea pig very sick or even die, so it's important to get at least 10mg of vitamin C into their systems each day.

You or I might drink a glass of orange juice, eat a packet of fruit snacks, or take a multivitamin.

Guinea pigs can get their vitamin C needs through fresh vegetables. Sometimes you may find that you can crush up a small amount of a vitamin C pill into their water, but this isn't always advisable because vitamin C is incredibly light sensitive, meaning it will lose its potency quickly when exposed to light.

Red pepper is a vegetable with an immense amount of vitamin C. Since some guinea pigs won't really take fondly to an orange, they're almost always ravenous for peppers.

Pellets will often claim that they have "long-lasting vitamin C", but you have to be aware that the bags will have been sitting on a warehouse shelf and may not even get into your hands as a consumer until months have gone by, at which time the vitamin C has been exposed to enough light and has been sitting long enough to have been mostly if not completely depleted.

As a sidenote, isn't the guinea pig in this picture cute?? She's my sweet little guinea pig Millie! Look at that cute little piggie lip. *swoon*