Nutrition

Guinea pigs are herbivores - this means they only feed on plant material. To keep their digestive system moving and their energy levels up, they need to graze throughout the day and night. The best type of food for this is fibre and fibre comes in the form of hay. 

Hay is made up of long fibres that help the muscles of your guinea pig’s stomach stay strong. A guinea pig's complex digestive system means they need to constantly snack on hay throughout the day to keep things moving inside and help prevent blockages.

Hay is also important for your guinea pigs’ teeth! Because a guinea pig’s teeth grow continuously throughout their life, they need to be worn down and kept at the correct length and shape by eating hay, grass, and leafy green plants.

Good quality, dry, sweet smelling hay should be available 24 hours a day, so your guinea pigs always have something to nibble on. Always make sure the hay you give is never damp, dusty or mouldy, as this could make your guinea pigs really sick.

It is a good idea to buy a hay rack or hay basket to hang on the side of the cage; hay left on the cage floor will easily become dirty, damp and mouldy from your guinea pigs’ toileting.

Vitamin C is essential for a guinea pig’s diet. Like humans, guinea pigs are unable to make their own vitamin C and require an outside source of vitamin C in the form of vegetables and fruits. This should be through safe, dark green leafy vegetables (NOT lettuce) Carrots, tomatoes, and other fruit have high sugar contents and therefore should be treat food, not a main source of vitamin C. 

If your guinea pigs do not get enough of vitamin C in their diet, their bodies' supply of vitamin C will disappear quickly, leaving them vulnerable to a condition called scurvy. This condition can mess with a body's ability to make collagen – this is an important ingredient for bone and tissue growth, so not having enough can cause all sorts of health problems.

Many guinea pig pellets have added vitamin C, however once the packaging is opened, some pellets will start losing the amount of vitamin C they contain. Therefore, you should not just rely on just these pellets to provide your guinea pigs with all their Vitamin C needs. 

It is a good idea to talk about your guinea pigs’ diet with their veterinarian. Your guinea pigs’ veterinarian can advise you on the best diet plan for them and may even recommend a daily vitamin C supplement in case they are not receiving adequate amounts in their diet.

High quality guinea pig pellet food is a readily available source of food for guinea pigs, providing a good source of vitamins, minerals, and other nutrients and fiber. 

Pellets should be a staple in your guinea pig's diet, along with hay and fresh foods. Only use pellet food made specifically for guinea pigs. 

Each of your guinea pigs will eat about 1/8 cup of pellets a day when also fed adequate hay and fresh vegetables. Always check the pellet feeding guidelines printed on the packaging and always ask your guinea pigs’ vet if you are ever unsure about their diet.

Buy your guinea pigs’ pellets in small quantities and store them in an airtight container in a dry, cool, dark place to preserve the strength of the vitamin C (look for pellets with an expiry date to check for freshness).

In addition to hay and pellets, provide your guinea pigs with a serving of the appropriate fresh vegetables daily. These will help to provide the essential vitamin C that your guinea pigs need, along with variety in their diet. 

Generally, a handful of vegetables per guinea pig, per day, are just the right amount. 

Remember to always wash fresh foods to ensure they are free of pesticide residue. If you're picking fresh vegetables, ensure that these are from a safe area that has not been sprayed by poison or chemicals that could harm your guinea pig. 

Always remove any uneaten fruit or veggies from your guinea pigs’ enclosure after about an hour so that you don't have an icky, mouldy mess in your guinea pig's home.

Fresh grass and garden greens are another key part of a guinea pig’s diet, as they also ensure good dental and digestive health. 

Guinea pigs love grass, dandelion leaves, puha, fresh safe herbs, plantain and dock leaves. Your family must make sure the area they pick these from is a safe area that has not been sprayed by poison or chemicals that could harm your guinea pig. 

Offer your guinea pigs a variety of safe, washed leafy greens or weeds every day – ideally five or six different types. 

Other safe plants include cabbage, broccoli, parsley and mint. Check online and ask your vet or local SPCA for ideas of other guinea pig safe herbs and garden greens you can grow for your guinea pigs.

Don’t ever feed your guinea pigs lawnmower clippings as these can upset their digestive system and make them ill.

Always check with an adult before feeding your guinea pig a picked plant. If they don’t know for sure what a plant is or whether it is safe, don’t feed it to your guinea pig!

• grass (free from chemicals)
• dandelion greens 
• puha
• dock (before it has flowered)
• white clover
• herbs such as: marjoram, borage marigold, nasturtium, rosemary
• chickweed 
• capsicum: green, orange, red (great for Vitamin C!)
• cucumber
• lavender
• bok choy
• radish tops
• turnip tops
• raspberry leaves
• beet greens
• parsley
• carrot tops
• silverbeet
• mint leaves
• romaine
• red/green cabbage
• cucumber
• snow peas

There are lots of fruits and vegetables that your guinea pig will like, but they are not good for them to have every day because of their high sugar contents.

These foods are good to feed your guinea pig a few times a week, but not every day:

• broccoli leaves and tops
• brussel sprouts
• kale
• spinach
• carrots
• celery has little nutrition and high water content, making it a good source of water on car trips, but not recommended as a daily food. You must always cut celery into small pieces because the stringiness of it can be a choking hazard.
• apples (no seeds)
• mint
• sage
• apricot
• kiwifruit
• tomato
• mango
• nectarine
• oranges and mandarins: have a high acid content so don't feed too much.
• papaya
• pears
• peach
• plums
• pineapple
• berries: blueberries, blackberries, raspberries, strawberries – feed a few times a week but not every day due to high sugar content.
• melons: cantaloupe, honeydew, watermelon – feed in small amounts since they have high water and sugar content

Never give your guinea pigs human foods like: chocolate, biscuits, crackers, breakfast cereal, yoghurt drops, milk, pasta, grain, nuts, seeds and bread. Also, no bananas, grapes, or corn. 

Avocado, hemlock, privets, beans, lettuce, rhubarb, buttercup (weed), jasmine, potatoes, lilies, snowdrop, mushrooms, sweet peas, daffodil, nightshade, foxglove, oaks are all highly toxic to guinea pigs and should never be given to them.

Muesli-style guinea pig food is a guinea pig’s version of junk food! 

Muesli-style guinea pig food is usually a mixture of pellets with dried fruit, nuts, grains and coloured pieces – they look a bit like human breakfast muesli. These mixes are high in fat, sugar and salt which are not good for your guinea pig. Some seeds are also choking hazards.

Many types of muesli-style guinea pig food are associated with health problems in guinea pigs and should not be fed. Feeding muesli-style guinea pig food can increase the risk of guinea pigs developing serious teeth and tummy problems (including obesity) which can cause terrible suffering. 

If your family currently feed your guinea pig muesli-style food, encourage your parents or caregivers to talk to your vet about gradually transferring your guinea pigs onto a healthier diet. Your guinea pigs will be much happier and healthier for it! This change should be done slowly over 14-28 days to avoid potentially serious tummy problems.

The importance of feeding your guinea pigs the right amount is just as important as choosing the right food for your guinea pigs. 

Guinea pigs tend to eat for long periods of time. Even at night time they like to graze, forage for food and be sociable. 

How much an individual guinea pig needs to eat depends on their age, lifestyle and general health. If a guinea pig eats more food than they need, they will become overweight and may suffer. When a guinea pig is really overweight, they have a reduced quality of life, such as not wanting to play or having difficulty breathing. It also causes serious health problems such as diabetes. Preventing obesity depends on having the right food in the right amounts. 

Try to avoid guinea pig pellets with dried fruit, nuts, grains and coloured pieces. These are high in fat, sugar and salt which are not good for your guinea pig. 

Different guinea pigs have different needs so always check with your guinea pigs’ vet if you are ever unsure of what, how much or how often to feed your guinea pigs.

Just like people, most of a guinea pig’s body is made up of water – 80% of it in fact!

Water is absolutely essential for every function of its body. A guinea pig needs water because without water, a guinea pig is not going to survive for very long.

Fresh, clean water must always be available and replaced daily for your guinea pigs.

Use heavy containers for your guinea pigs’ water to avoid it knocking over and spilling, or use guinea pig sipper bottles that clip to the side of your guinea pigs’ enclosure. Plastic or glass sipper bottles are best for supplying water for hygiene reasons; however, the bottles and the spouts need to be cleaned at least weekly.

Take note of the amount each guinea pig eats and drinks every day and watch out for any changes in an individual’s eating, drinking or toileting habits. For example, if the number of droppings gets less or stops, or if there are soft droppings sticking to his or her back end, ask your parents or care-givers to talk to your vet straight away as your guinea pig could be seriously ill.