Guinea pigs make great pets, but knowing what to feed them can sometimes be challenging. They need to be fed a specific guinea pig diet or they can end up with nutritional deficiencies which can lead to health issues. In this article, we take a look at some of the essentials and how you can keep your guinea pig happy and healthy.

So what foods should we feed them?

Guinea pigs are herbivores, which means they only eat plant based foods and do not eat meat. A guinea pig’s diet should consist of 80% good quality hay and/or fresh grass, 15% fresh greens and vegetables suitable for guinea pigs, and 5% of a complete guinea pig pellet food. 

Grass and Hay

80% of a guinea pig’s diet should consist of good quality hay and/or grass. It is often not possible to provide all of this as fresh grazing grass, so hay should always be offered ad lib (freely!) so your guinea pigs can eat to their appetite. The hay should be good quality suitable for eating, such as timothy hay.

If your guinea pig has access to an outdoor run area where they can graze grass. It is important this grass is fresh and free from insecticides or pesticides which can be toxic if ingested.

Greens and Vegetables

15% of your guinea pig’s daily diet should consist of greens and vegetables. It is important these are nutritious, safe to eat and contain vitamin C. Examples of good options for guinea pig proof veggies include spinach, broccoli, kale, bell peppers, rocket and chicory. Carrots should only be fed in very small amounts as a treat, as they are high in sugar which can cause health issues if too much is consumed.

You can find a complete list of appropriate greens and vegetables for guinea pigs here.


Only 5% of the guinea pig’s diet should consist of a complete nutritionally balanced pellet food. Guinea pig specific complete pellet foods are available at most local pet stores. The amount to be fed is usually written on the back of the packet. It is important you do not feed more than the recommended amount as this can lead to obesity. 

Muesli and similar food types which are bright and colourful may look appealing, but they offer the option for your guinea pig to pick out the nice bits and leave the healthy bits. As a result they can end up having a very unbalanced diet.

Vitamin C

Vitamin C is an essential nutrient, which is important in keeping body cells healthy. Guinea pigs can’t make their own vitamin C (unlike most animals), so they need to get it from their diet. Without it, guinea pigs are at risk of health issues including Scurvy. Many vegetables contain good levels of vitamin C, including spinach, broccoli, bell peppers and tomato, as do guinea pig specific pellets.

The good news is as long as you feed a balanced diet with a variety of vegetables containing vitamin C, you don’t need to worry about supplementing it. If you have any questions, or are concerned your guinea pig’s diet is not balanced enough, then speak to your local veterinarian who will be able to advise you further. 


Water is an essential part of all animals’ diets and is often overlooked. It is vitally important your guinea pig always has access to fresh clean drinking water which is accessible. Plastic drinking bottles with a metal spout are a good option and available from most local pet stores. They need to be cleaned regularly with guinea pig safe disinfectant to ensure harmful bacteria does not build up.


Guinea pigs need a specific, nutritionally balanced diet. This should include;

  • Hay and grass should make up 85% of a Guinea pigs diet
  • Guinea pigs can’t make their own vitamin C so must get this from their diet
  • Clean fresh drinking water should always be available 

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