A complete guide to the proper guinea pig diet.
Looking to get your first guinea pigs but not sure what you’ll need to feed them? Guinea pigs do require a specific diet that is a little bit more complicated than just scooping some pellets into a dish every day. This guide will give you all the basics on what guinea pigs eat so you can provide the right diet to keep your pets happy and healthy.
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What Do Guinea Pigs Eat?
Before we get into the specifics on what to feed your guinea pig, first let’s talk a bit about the digestive system of a guinea pig.
The digestive system of a guinea pig is designed to constantly have food moving through it. If you think about how a guinea pig would behave in the wild, they would be constantly grazing on grass and plants. We want to be sure to providing a diet to our guinea pigs that allows for food to be continually moving through their system.
The proper guinea pig diet is vital to keep their digestion working the way it should and avoid major health issues. Keep this in mind as you learn more about what guinea pigs eat!
Vitamin C For Guinea Pigs
Something else that is important to know when it comes to feeding your guinea pigs, is that guinea pigs are not able to produce their own vitamin C. This means we need to make sure we are providing our pets with enough of this vitamin through their diet.
We’ll touch more on feeding vegetables to guinea pigs in a little bit, but I want to quickly go over what NOT to give your guinea pigs for vitamin C.
Pet stores sell vitamin C drops that are meant to be put into the water of guinea pigs. You DO NOT want to use these. They are almost useless – vitamin c is only effective for about 20 minutes once exposed to the water and light.
Unlimited High-Quality Hay
The most important part of a guinea pig’s diet is hay. 90% of their diet should be made up of fresh, high-quality hay that is always available to them. Your guinea pig should never be without hay.
We talked about there needing to be food constantly moving through a guinea pig’s system. Hay is the best food for this job. Providing unlimited hay at all times means that your piggy can be constantly eating it and keeping their digestion moving.
Hay is also important to keep your piggy’s teeth worn down correctly. Since guinea pigs are rodents, they have constantly growing front teeth. These teeth can get too long if your pet is not chewing enough to keep them worn down. The constantly chewing motion that comes from a piggy eating a lot of hay will keep the teeth worn down.
The two most popular types of hay to feed guinea pigs are timothy and orchard grass. 2nd cut timothy is the most common and provides all the nutrients that a guinea pig needs. Orchard grass is also great for them and is a good option if you are allergic to timothy hay.
You don’t want to be feeding your guinea pig alfalfa hay unless they are under 6 months old. Alfalfa has too much calcium for adult piggies and can add to the risk of them developing a bladder stone.
READ MORE >> The Importance of Hay for Guinea Pigs
Fresh Veggies Every Day
Pet stores often don’t tell new piggy owners that their new pets require fresh veggies every single day. Fresh vegetables provide the additional nutrients and vitamins guinea pigs need that they don’t get from their hay.
A general rule of thumb is to feed about a cup of veggies per guinea pig each day. The regular veggies I feed are green leaf lettuce, green bell pepper, cilantro, and cherry tomatoes. But variety is important for a guinea pig! There is a wide variety of different vegetables that are safe and healthy for guinea pigs but balancing the veggies can be a little bit overwhelming for new owners.
Check out this full article on feeding vegetables for guinea pigs – and grab your free list of safe veggies!
Healthy Guinea Pig Pellets
Pellets are actually a very small part of a healthy guinea pig diet.
Guinea pigs should only receive a limited amount of pellets. The rule of thumb is 1/8 cup of pellets per guinea pig per day. You don’t want to be constantly filling up their dish any time it’s empty.
A lot of the guinea pig pellets sold in pet stores are not healthy options. The ideal guinea pig pellet should be just plain pellets with no added colorful bits included. Nuts and seeds should also not be included. You want a timothy-hay-based pellet for adult guinea pigs and an alfalfa-based pellet for young guinea pigs.
The pellets that I recommend are the Oxbow Garden Select Adult Guinea Pig Pellets. These are considered one of the healthiest options on the market and provide what guinea pigs need without a ton of extra unhealthy ingredients. You also can find them in most pet stores, as well as online.
Guinea Pig Supplements
Guinea pigs don’t really need much in the way of supplements. However, there are a few great support tablet options on the market that you can give to your pigs to keep them healthy.
Oxbow makes support tabs for a variety of different things that you can use. My favorites are the Oxbow Vitamin C tabs and the Oxbow Urinary Support tabs.
Sherwood Pet Health also has support tab options that are pretty popular. I’ve found with these that my piggies are a little less likely to eat them.
You can usually feed the support tabs just like you would a treat – my guinea pigs love the Oxbow tabs. It’s a great way to trick them into eating something healthy as a treat!
Treats for Guinea Pigs
Guinea pigs absolutely love getting treats, but you don’t want to be going overboard on how many you’re feeding.
My favorite treats to give my guinea pigs are small pieces of fruit (both fresh and dried). Fruit generally has more sugar than veggies, so it works great as an occasional sweet treat. Some veggies have a higher sugar content that also are great as treats (make sure to grab my printable list if you haven’t already!)
There are also quite a few treat options on the market and sold in pet stores. Most of these are not healthy – guinea pigs shouldn’t have nuts, seeds, alfalfa hay, yogurt, dairy, or flour-based treats.
If you want to buy treats from the pet store, the best ones I’ve found are all from Oxbow. I like the Oxbow baked treats and the Oxbow Simple Rewards treats.

Forage for Guinea Pigs
Something else that is optional but can be a great way to provide your guinea pig with variety is forage. Forage is basically a mixture of dried herbs and plants. You can offer it directly to your pet as a treat or mix it in with hay. Forage provides healthy plants that your piggy would otherwise not get to have.
Forage can be a little bit difficult to find in the United States. My favorite place to order it is from Small Pet Select. They have a lot of great options that are safe and healthy for your guinea pigs.
You also can get forage in guinea pig subscription boxes. My favorite one is Piggie Box. It comes from the UK, so you can get forage options that are not able to be found here in the US.
Final Thoughts on What Guinea Pigs Eat
Providing the right diet to your guinea pig is an important part of making sure they are healthy and happy. Providing unlimited high-quality hay, fresh veggies every day, a small amount of healthy pellets, and the occasional treat will provide a great nutritional foundation for your pet!
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