What do guinea pigs eat? If your answer is “pellets and hay,” you’re only half right. The foundation is Timothy hay (80% of their diet), but they also need fresh vegetables daily and vitamin C supplementation. My first guinea pig refused to eat cheap pellets, and she was right to hold out for better.
Here’s what a healthy guinea pig diet really looks like: The absolute foundation of what a guinea pig eats is Timothy Hay (80% of their diet). They also need 1/8 cup of high-quality Vitamin C pellets and about 1 cup of fresh, safe vegetables daily.
The Daily Foundation: Hay and Pellets
Before we get to fresh veggies, you must understand the non-negotiable foundation of any guinea pig diet:
- Unlimited Timothy Hay: Your piggy should have access to fresh Timothy hay 24/7. Hay provides the crude fiber (20%+) needed to keep their constantly growing teeth filed down and their digestive system moving. Never use alfalfa hay for adult guinea pigs—it’s too high in calcium and protein and can cause bladder stones.
- Vitamin C Fortified Pellets: Feed 1/8 cup per pig per day. Look for plain, uniform pellets without colorful pieces, seeds, or dried fruit. The colorful mixes are unhealthy and encourage selective feeding.
Celery: Crunchy but Tricky
Yes, but with a major warning. Celery is safe and crunchy, which is great for their teeth. However, the stringy fibers in celery stalks can pose a severe choking hazard.
- How to serve: Always chop celery into very small, bite-sized pieces (about half an inch) to break those long strings before feeding it to your piggy. Many owners peel the strings off entirely for extra safety.
Carrots and Cucumbers
- Carrots: Yes, they love them! But carrots are surprisingly high in sugar and Vitamin A. They should be treated as a snack, given only 2-3 times a week, rather than a daily staple. A single thin carrot slice per pig is plenty. Don’t forget, carrot tops (the green leafy part) are also safe and actually healthier than the root itself!
- Cucumbers: Yes! Cucumbers are fantastic for hydration, especially during the summer. However, because they’re mostly water and have low nutritional value, feeding too much can cause soft stools. Two or three small cubes per pig is ideal.
Broccoli and Spinach: Feed with Caution
Not all greens are created equal. You need to be careful with these two:
- Can guinea pigs eat broccoli? Yes, but broccoli is a “gassy” vegetable. Guinea pigs can’t pass gas easily, and too much broccoli can cause painful bloating, which can be fatal if severe. Offer small florets only once a week.
- Can guinea pigs eat spinach? Yes, but sparingly. Spinach is high in Vitamin C, which is great, but it’s also extremely high in calcium and oxalates. Too much calcium in a guinea pig’s diet leads to deadly bladder stones. Serve baby spinach only once every two weeks as a rotational green.
Daily Veggie Rotation: A Sample Plan
A healthy weekly rotation to keep your piggy excited and well-nourished:
| Day | Morning Veggies | Evening Veggies |
|---|---|---|
| Mon | Romaine lettuce (2 leaves) | Bell pepper (2 slices) |
| Tue | Cucumber (3 small cubes) | Cilantro (small bunch) |
| Wed | Romaine + carrot (1 thin slice) | Bell pepper |
| Thu | Zucchini (2 small pieces) | Cilantro |
| Fri | Romaine + tiny broccoli floret | Bell pepper |
| Sat | Cucumber + carrot top | Cilantro |
| Sun | Romaine + treat fruit piece | Bell pepper |
Foods to NEVER Feed Guinea Pigs
Just as important as knowing what to feed is knowing what to avoid:
- Iceberg lettuce: Contains lactucarium, which can be toxic, and has almost no nutritional value.
- Potatoes and potato peels: High in starch and contain solanine, which is toxic to guinea pigs.
- Rhubarb: Highly toxic—can cause kidney failure.
- Chocolate, candy, or any processed human food: These can be fatal.
- Meat, dairy, or eggs: Guinea pigs are strict herbivores and can’t digest animal protein.
- Avocado: Contains persin, which causes respiratory distress and heart failure.
I buy Timothy hay in bulk online — it’s fresher and way cheaper than the small bags at pet stores. Your piggies will notice the difference.
