Diet for a Guinea Pig

Guinea pigs are herbivores (plant eaters). A healthy diet includes:

• Unlimited, good-quality grass hay (such as timothy or orchard grass)

• A measured amount of commercial guinea pig pellets (about 2 tablespoons daily)

• Fresh vegetables daily

• Occasional fruit as a treat

Offer good-quality grass hay (such as timothy or orchard grass) as the main food in your guinea pig’s diet. Hay is best offered in a hay rack to keep it clean and dry. Chewing on hay not only will help wear down your guinea pig’s continually growing teeth but also will provide the fiber your pet needs for proper digestion.

For other foods, use a small, heavy ceramic dish that can’t be tipped easily. Leafy greens (carrot tops, romaine, green or red leaf lettuce) are popular. Avoid iceberg lettuce (it’s mostly water). High-calcium greens (parsley, kale, spinach) should not be given often, because excess calcium may contribute to bladder stone formation. Offer small amounts of carrot or high-fiber fruit (apple, pear) only as treats—fruits are high in sugar and can cause digestive upset if overfed. Remove uneaten fresh food after a few hours to prevent spoilage. Hay should be available at all times.

Feed about 2 tablespoons (1/8 cup) of good-quality guinea pig pellets daily. Choose pellets that are high in fiber and low in carbohydrates. Alfalfa-based pellets are higher in calcium and are suitable for young, growing, or pregnant guinea pigs. For adult guinea pigs, timothy-based pellets with less calcium are preferable. Ask your veterinarian for pellet recommendations.

Guinea pigs are often picky and form food preferences early. When getting a new guinea pig, try to maintain the diet it’s used to, or introduce new foods slowly. Offer a variety of high-fiber pellets, small amounts of vegetables, and limited fruit to broaden its diet.

Yes, especially vitamin C. Guinea pigs can't produce vitamin C, so they need to obtain it from their diet. Guinea pig pellets are fortified with vitamin C, but it breaks down over time. Pellets can lose a substantial amount in just a few months, so it's best to buy fresh pellets regularly and supplement them with vitamin C–rich fresh vegetables and fruits. Don't substitute rabbit pellets, because they don't have enough vitamin C for guinea pigs. Talk with your vet about the best vitamin C sources and amounts for your pet.

Fresh water must be available at all times to prevent dehydration. A drip bottle attached to the cage at a reachable height keeps water cleaner than an open bowl. Clean the bottle daily and refill with fresh water. Don't add supplements to the water. Avoid distilled water or water with very high mineral or calcium content.