Guinea pigs are wonderful pets that are relatively easy to care for. With proper nutrition and veterinary care, many pigs can live for 5 or more years. Keeping a guinea pig happy and healthy starts with a solid understanding of their dietary needs.
Grass hay is the most important staple in a guinea pig’s diet. It should compromise around 75% of their diet. Other important dietary additions are vitamin C supplements, a small amount of guinea pig-specific pellets, vegetables, and water. Fruits may be used as treats only and given sparingly. Fruit should be less than 5% of your guinea pig’s diet.
Foods for Guinea Pigs
Guinea pigs have a relatively high metabolic rate and require nearly continuous eating. They are strict herbivores and should never be offered animal protein.
Like most mammals, some foods are much better for guinea pigs than others. While there are commercially available pellet products for guinea pigs, some including seeds and nuts, feeding your guinea pig a diet of only pellets will lead to many health issues. Guinea pigs should never receive seeds or nuts, and pellets should only be a minimal part of their diet.
Many pet stores and companies produce items marketed for guinea pigs with little or no safety research. In some cases, the products are directly harmful to cavies. Keep this in mind when purchasing supplies for your guinea pig. Just because a product claims to be good for a guinea pig doesn't mean it always is!
What Do Guinea Pigs Eat?
Hay is the most important part of your cavy’s diet. Guinea pigs should have unlimited, 24/7 access to high-quality grass hays. Timothy and orchard grass hays are popular, but guinea pigs also do well with meadow, oat, or brome hay. Unlimited access to hay helps prevent common dental and gastrointestinal disorders.
Grasses are abrasive and help to wear down the continuously growing teeth of a guinea pig. Without this stimulation, teeth easily become overgrown, abscessed, or make the cavy unable to eat normally. Alfalfa or clover hay should be used only in juvenile or pregnant cavies, as it is high in calories and calcium, leading to obesity, abnormal calcification, and bladder stones. Most veterinarians recommend Oxbow hay products for their safety and nutritional value.
Vegetables are the next important part of a cavy’s diet. Use caution when introducing new food items, as it may cause gas or diarrhea. Once your guinea pig is familiarized with many vegetables, you can offer ½ to 1 cup of a mixture daily. Aim for two or three different types of vegetables each day.
Pellets can be offered in limited quantities—typically 1-2 tablespoons per cavy. Make sure to use guinea pig–specific pellets. High-quality grass pellets are an important part of a cavy’s diet but are never a replacement for hay. Always make sure to provide unlimited grass hay in addition to small amounts of pellets. Veterinarians typically recommend Oxbow as a high-quality and safe brand. Never feed pellets with seeds, nuts, or dried fruits.
Fruits and treats should be offered sparingly—once or twice a week, not daily. These often are empty calories with no nutritional value to the cavy. Treats are high in sugar as well, leading to obesity and GI issues. Many guinea pigs enjoy alfalfa cubes, carrot tops, and apples as the occasional treat.
Vitamin C is a required supplement for all cavies. Unlike many other species, guinea pigs cannot produce their own vitamin C, so they must obtain it from their diet. Low vitamin C leads to conditions like scurvy and other illnesses. If your guinea pig is sick with any illness, additional vitamin C may be required, but always ask your veterinarian for the amount for your pet. Oxbow is a trusted brand of supplemental vitamin C.
Veterinarians do not recommend adding vitamin C to the water, as it can degrade quickly and also taste abnormal, thus decreasing the amount the guinea pig is willing to drink and possibly lead to dehydration. Many guinea pig pellets are also fortified with vitamin C, but because of the degradation through exposure to light, heat, or dampness, they may not have nearly enough. The most trusted way to provide supplemental vitamin C is through tablets, in addition to vegetables high in vitamin C.
Water should be provided at all times. Most guinea pigs do best with a sipper bottle attached to the side of the cage. However, inspect it frequently because many guinea pigs like to play with and chew the bottles.
What Fruits Can Guinea Pigs Eat?
Fruit should be given sparingly, as it can cause painful gas and fruits are high in sugars and empty calories. Fruits should be given as treats and compromise 0-5% of the daily diet. Reasonable fruits that guinea pigs enjoy occasionally include:
What Vegetables Can Guinea Pigs Eat?
Guinea pigs can be introduced to a variety of vegetables. Each new food item should be slowly introduced, so as to not cause any gastrointestinal upset or diarrhea. Once a vegetable is established, the guinea pig should receive multiple types every day. Pet parents should periodically rotate through all the vegetables not only to provide enrichment and prevent boredom, but to also provide a quality balance of vitamins and minerals. Some common vegetables for guinea pigs are:
- Romaine lettuce
- Leaf lettuce
- Dandelion greens
What Can Guinea Pigs Not Eat?
Some foods should never be offered to guinea pigs. Some foods, such as peppers and cucumbers, are not directly harmful, but may cause excessive gas and bloating in some cavies and should be avoided in excess. Foods that should never be in a guinea pigs diet include:
- Nuts, seeds, dried fruits
- Meat products
- Rabbit pellets, or pellets made for any other animal
- Multivitamins (vitamin C is required, multivitamins may cause other diseases unintentionally)
- High starch foods like peas, beans, corns, cakes, cereal, grains, bread
- Spoiled or unwashed foods—if it is not safe for human consumption, they should not be offered to a cavy
Foods to give sparingly, if at all include:
- Cruciferous vegetables such as cabbage, collards, bok choy, and broccoli may cause gas
- High oxalate greens, such as kale, spinach, chards, and collards may promote bladder and kidney stones
- Commercial treats, such as yogurt drops, have excess sugar and fat causing obesity and other health concerns. If fed in excess, may cause a cavy to not eat the other nutritious parts of their diet.
Johnson-Delaney, DVM, Dipl ABVP. Veterinary Information Network, Inc. Guinea Pig or Cavie (Cavia Porcellus) Pet Care. January 2021.
Guinea Lynx. Raising a Healthy Guinea Pig. 2022.
Pollock DVM, DABVP, Christal. Parmentier DVM, Sylvia. LafeberVet. Basic Information Sheet: Guinea Pig. October 2018.
Horton DVM, Susan. Chicago Exotics Animal Hospital. Guinea Pig Care.
San Diego Zoo Animals & Plants. Guinea Pig. 2022.
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