How much to feed
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.
Commercial food: Choose vitamin C-fortified pellets with no seeds or dried fruit added. 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. About 1/8 cup of pellets once a day—supplemented by hay and fresh vegetables as described below—will be enough.
Timothy hay: Provide an unlimited quantity of fresh timothy hay every day. Guinea pigs need continuous access to hay to aid their digestion and limit the growth of their teeth.
Fruit and vegetables: Fresh vegetables can be offered once a day and should be equivalent to about one cup total per guinea pig per day. Leafy greens like romaine lettuce, kale, cilantro or parsley should comprise the bulk of your pig’s fresh produce. Vegetables like red or green pepper, broccoli and tomatoes have high levels of vitamin C in them and are great daily options. Add carrots, zucchini and sweet potato once or twice a week.
Fruit works well as an occasional treat that is offered once a day or several times a week. 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. Kiwis, strawberries and citrus have high levels of vitamin C.
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.
Time for treats
There are a variety of commercial treats marketed for guinea pigs and other small animals. Loaded with artificial sweeteners such as high fructose corn syrup, fructose or sucrose, they provide little nutritional value and 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.
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.
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.
Keep it fresh
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.