What can guinea pigs eat?

And how much? Guinea pigs don't usually overeat, but it's important to provide the proper balance of pellets, hay and fresh vegetables. Like human beings, guinea pigs cannot make their own vitamin C, so they require vitamin C-rich foods in their daily diet. Inadequate vitamin C can lead to scurvy, signs of which include a weakened immune system, abnormal bone and tooth development and growth, and delayed wound healing. An inadequate diet can also lead to obesity, dental disease, bladder stones and gastrointestinal problems. 

Grass hay

An unlimited quantity of fresh grass hay daily is the cornerstone to a healthy guinea pig diet. It should be around 80% of their diet. Guinea pigs need continuous access to hay to aid their digestion and limit the growth of their teeth. For guinea pigs over a year of age timothy or orchard hay are suitable, but for younger guinea pigs alfalfa hay provides more calcium for growing bones. 

Commercial food

Choose timothy-based vitamin C-fortified pellets with no seeds or dried fruit added. About 1/8 cup of pellets once a day—supplemented by hay and fresh vegetables as described below—will be enough. Because vitamin C usually degrades rather quickly, it is crucial to also offer your guinea pig vitamin C-rich vegetables and fruit on a daily basis. Buy in smaller portions to maximize the effect of the added vitamin C, as it oxidizes rapidly once the bag is open. 

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Fresh vegetables can be offered once a day and should be equivalent to 1/2 to one cup total per guinea pig per day. Leafy greens like romaine lettuce, red and green leaf lettuces, mustard or turnip greens, cabbage, kale, cilantro and parsley should comprise the bulk of your pig’s fresh produce. It’s best to provide variety by feeding different greens each day. Vegetables like red or green pepper and broccoli have high levels of vitamin C in them and are great daily options. Add carrots, zucchini, tomato or sweet potato once or twice a week.

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Fruit works well as an occasional treat that is offered once a day or several times a week. Kiwis, strawberries and citrus have high levels of vitamin C. Keep the portion size small since fruit is high in sugar; a small wedge of orange or apple, several blueberries or a thin slice of banana is perfectly adequate. 

Introduce new fruits and veggies gradually to avoid diarrhea. If your guinea pig develops loose stool, reduce the amount of fresh produce for several days, then reintroduce it in smaller portions.


Because guinea pigs are susceptible to developing painful bladder stones, and some bladder stones are comprised of calcium oxalate, reducing or eliminating foods high in oxalates—such as spinach, parsley and strawberries—can provide benefit in guinea pigs who develop calcium oxalate stones. Read a more detailed explanation and consult a veterinarian who specializes in guinea pigs with specific questions about diet. A diet high in fresh hay and plenty of fresh water are paramount to preventing urinary issues in guinea pigs. 

Feeding tips

  • The steady amount of produce in your guinea pig's diet means that you need to be conscientious about removing uneaten fruits, veggies and other perishable foods before they spoil.

  • Check for untouched or unfinished treats an hour or so after they’ve been offered to your guinea pig.

  • Replace pellets on a daily basis. Guinea pigs often kick bedding material or droppings into their food bowls and stale pellets will have little, if any, vitamin C.

  • If there are many pellets left in the food bowl every day, you’re probably giving your pig too much. An eighth of a cup is all that's needed.

  • Guinea pigs eat their own stool at times to supplement their nutrition. It is normal, so don’t be alarmed and do not try to interrupt this practice!

Time for treats

There are a variety of commercial treats marketed for guinea pigs and other small animals. Most are loaded with artificial sweeteners such as high fructose corn syrup, fructose or sucrose and provide little nutritional value with lots of empty calories.

Commercial treats are unnecessary and a waste of money. Your pig will be perfectly happy with high quality pellets and hay and treats of fruits and vegetables. For a special snack, try mixing some rolled oats into your guinea pig’s pellets or stuff a small cardboard tube with fresh hay. Often guinea pigs “wheet” for their favorite food, and will take their favorite fruit out of your hand. 

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Multivitamins and mineral wheels

Mulitvitamins and mineral or salt wheels are marketed as supplements to your guinea pig’s diet, and the wheels are also advertised as outlets for gnawing. But if you’re feeding your guinea pig a varied and well-balanced diet, these products shouldn't be necessary.

The glues and adhesives that hold mineral and salt wheels together may be harmful. Furthermore, the bleaching process for salt wheels introduces unnecessary chemicals into your pig’s diet. Although there isn’t consensus on these products, they should be considered a low priority when considering how best to spend your pet supply budget.

There are times when a veterinarian will recommend an additional vitamin C supplement for a guinea pig that is picky or having health issues. The best options are pediatric vitamin C drops given daily, or vitamin C tablets formulated for guinea pigs. Water additives are not recommended, as they degrade quickly and can make the water less palatable. 

A delish dish

Opt for a ceramic food dish rather than a plastic one. Ceramic dishes are sturdy, chew-resistant and difficult to overturn. They're also durable and shouldn't need to be replaced unless they become cracked or chipped.

Look for a wide, shallow bowl. Many guinea pigs like to place their front feet on the rim of their food bowl when they eat and this design will lessen the chances that the bowl (and your pig!) could be upended.
Place the food bowl in an area of the cage that's far away from your guinea pig's bathroom area.

Spot clean your guinea pig's food bowl as needed throughout the week if they kick bedding or droppings into it. Wash the bowl with soapy water and rinse and dry thoroughly during the weekly cage cleaning.

Hanging water bottles work well for most guinea pigs. However, they also must be kept clean. Wash with soap and water weekly, using a brush or pipe cleaner to clean the tube they drink from. Take special care daily to ensure that it is still dispensing water. The spout apparatus can jam with debris and stop working. No-tip bowls can also be used and must be changed daily. 

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Be sure to discuss this general advice with a veterinarian to ensure the best diet for your guinea pigs.