A common question for new guinea pig owners is “What can guinea pigs eat?”. If you want an at-a-glance look, check out the infographic I made on the topic. This is a more detailed list with advice based on actual scientific research. Diet plays a huge role in determining the health and longevity of your guinea pig, so it’s worth a few minutes to make sure you’re providing the optimal daily diet.
Guinea Pig Daily Diet in a Nutshell
An adult guinea pig weighing around 2 pounds should have a daily diet that consists of:
It should be always available to your guinea pig. Ideally, grass hay should make up about 75% of his daily diet. Timothy Hay is the best option for guinea pigs, but alternatives you can use are rye grass, oat hay, bluegrass, brome or orchard hay/grass. Alfalfa hay is a legume-based hay, not a grass hay. Alfalfa hay has more protein and calories than Timothy Hay, and also less fiber. You can use alfalfa hay for nursing or pregnant guinea pigs, but Timothy Hay is a much better choice most of the time.
Look for pellets that contain stabilized Vitamin C and that have an expiration date marked on the packaging. A 2-pound guinea pig should eat 1/8 – 1/4 cup of pellets per day. The Oxbow brand offers a popular, high-quality guinea pig food. Be sure not to substitute rabbit pellets with guinea pig pellets, because they are not the same. Rabbit pellets do not usually contain Vitamin C, and sometimes rabbit pellets may contain chemicals or additives that are harmful to guinea pigs.
Guinea pigs are herbivores and need fresh vegetables daily. 1 cup per day is ideal. Some vegetables are better than others when it comes to guinea pigs, however, so I’ve included a list below of ideal vegetables and those that should only be given occasionally. Make sure you wash the vegetables to remove wax and pesticides.
Most fruits are suitable for guinea pigs, but limiting fruit to a couple times per week may be best. Fruit contains sugar, and guinea pigs don’t need a lot of sugar. Some owners give fruit 1-2 times a week in small amounts. Other feed a small amount daily. It’s up to you how much to give, but I think a couple times per week is plenty.
Fresh, clean water should always be available. The best way to keep it clean is to supply it in a water bottle. It’s a good idea to NOT add supplements (e.g., Vitamin C) to the water because it can make the water taste bad, it’s not an optimal way to ensure the guinea pig ingests the supplement, and it can degrade or oxidize while sitting in the water, thereby making it non-effective. A minimum of 5 ounces of water a day is essential.
- bib lettuce
- clean, pesticide-free grass
- green or red pepper
- mustard greens
- red leaf lettuce
- romaine lettuce
- Swiss chard
- turnip greens
Occasional Vegetables (Small amounts once in a while)
- Bok Choy (may cause gas or bloat)
- Cabbage (may cause gas or bloat)
- Corn husks
- Forages like chickweed, dandelions, and young clover and plantain
- iceberg lettuce (no nutrients and may cause diarrhea)
- sweet potato
- Apple, no seeds
- crab apples
- grapes (must be seedless)
- tomato (remove top green part)
Never feed – Forbidden
- Dairy products
- Rabbit Pellets
- White Potatoes
Be Careful with…
- Commercial Treats
These can contain lots of artificial colors, additives, and chemicals that are not good for your guinea pig. Sometimes they contain high fructose corn syrup. Oftentimes, they offer high fat and calories with little to no nutritional value. So be sure to read the label and make a sound decisionbefore you spend your money on them.
- Vitamin C
Guinea pigs need Vitamin C and must obtain it through their diet. They should ingest 30-50 mg per 2 pounds of body weight per day. They get it from the hay, the vegetables, the pellets, and the fruit they eat. If you supplement with Vitamin C, it’s best to administer it with a syringe directly into the mouth rather than putting it in the water. If you give them a varied diet with lots of fresh fruits and vegetables, you shouldn’t need to so any supplementation. Vitamin C is water soluble, meaning and extra will just get excreted. It’s nearly impossible to overdose on Vitamin C. In addition to enhancing the immune system, Vitamin C is essentail for the development and maintenance of skin and mucosal membranes (like gums).
- Vitamin A
Guinea pigs should be getting between 1.67-9.9 mg of Vitamin A per day for a 2-pound animal. Again, if you’re providing a well-rounded diet, his needs should be met. Vitamin A is fat soluble, meaning excess gets stored and cn build up, leading to an overdose. So it’s not a good idea to supplement with Vitamin A.
Again, if the dietary guidelines listed above are followed, your guinea pig should be getting enough fiber. Ideally, 20% of a guinea pig’s daily diet should be fiber.
- BE CAREFUL WITH CALCIUM
Of course, guinea pigs need calcium, but too much can lead to problems. Guinea pigs are prone to kidney stone and bladder stone formation, especially as they get older, and too much calcium may be a causative factor for bladder stones. Phosphorus can be a causative factor, too. The ideal ratio of calcium to phosphorus in the diet is 1:3, 1 part calcium to 3 parts phosphorus.
Guinea pigs practice coprophagy, that is, they eat their own feces. It may look and sound disgusting, but it’s a necessary practice. “Cecotropes” (soft feces) supply both Vitamin B and Vitamin K to guinea pigs. Guinea pigs deprived of cecotropes will eventually develop malnutrition and die.