1 The recommended ratio of food groups
2 Hay and fresh grass
3 Vegetables, fresh herbs and fruit with an illustrated balanced sample diet
4 Special dietary needs
- Urinary tract infections, bladder stones and sterile IC (non-bacterial interstitial cystitis)
- Diabetes and long term digestive problems
- Impaction in boars
- Pregnancy and nursing dietary tweaks (only visible to registered members who have accepted our no intentional breeding policy)
5 Common veg list: How much and how often?
6 Pellets
7 Water
8 Forage, seeds and treats- safe and unsafe
9 The life-saving importance of weighing weekly
10 Tips on how to save on your piggy food bill
11 Running out of certain foods? - Practical advice
Sadly for new guinea pig owners, we do not have the ultimate ideal guinea pig diet yet! New insights will lead to new recommendations and trends.
There is as yet not as much research into guinea pigs as into other pet species; so things are bound to change as more is becoming known. Currently there is a lot of contradictory information around which can be very confusing. We are trying to keep abreast of developments and also include our own practical positive experiences as we go along, so it is always worth to re-read this guide from time to time!
This thread is aiming to help you develop your own diet that is based on your guinea pigs’ individual tastes and preferences and the availability/practicalities of what you can buy, grow, store and use up within reason.
1 The recommended ratio of food groups
The diet on which guinea pigs have evolved on and for which their dental and digestive system is laid out for basically falls into just two categories - mainly grass fibre and some supplementary forage. This supplementary category has split into many different undergroups, so it is very easy to lose sight of diet as a whole. Far too many owners also fall into the traps of treating treats as a dietary non-entity.
Additionally, the hardness and mineral content of the local water also needs to be taken into account; even more so in a mainly hard water country like the UK.
The recommended food group ratio per piggy per day
1 ca. 75-80% hay and fresh grass (unlimited and refilled at least once a day, preferably more often)
2 ca. 20-25% original supplementary wild forage:
- ca. 15-20% preferably green veg, fresh forage and fresh herbs (ca. 1 cupful / 50g / nearly 2oz)
- ca. 5% pellets or dry forage (1 tablespoon)
- any treats, including alfalfa and rich hays, are coming out of this group budget!
3 fresh plain cool/drinkable water daily (calcium content needs to be factored into the overall diet)
You can tweak the calcium intake within the supplementary group by - for instance - dropping pellets altogether and/or by filtering water etc. in order to feed a bit more high calcium veg (which also contain vitamin C and otherwise not supplemented magnesium). Please do not try to eliminate calcium altogether; it is essential for long term health. There is a locally dependent soft spot in the diet, each side of which - too high or too low - you can get stones or crystals.
2 Hay and fresh grass
Unlimited fresh hay should make the bulk of a guinea pig diet. It is vital for good gut and general health and to keep the all-important grinding back teeth ground down evenly.
Guinea pigs have evolved by eating grass in its fresh and dried form with supplementing their diet with some forage and any rare fruit they come across. What most people are not aware of is that fresh growing grass is actually high in vitamin C and that even hay contains it, if not in high concentrations.
This is the reason why guinea pigs have never had the need to make their own vitamin C. Because hay and grass are not part of a human diet, this food group has been generally blended out and been treated as if it didn't contribute any nutrients to the overall diet. The opposite is in fact true - hay and fresh grass are by a very long margin the mainstay of the diet and should make around 80% or more of what a guinea pig eats in a day. This can really add another 1-2 years to a healthy guinea's life and take it from the bottom of the average life span to the higher end and beyond.
Please always offer unlimited hay to your guinea pigs at all times (even when they have access to the lawn); too much fresh feed can cause digestive problems. It is the one food group you really can't do without!
The more your diet resembles the natural diet of guinea pigs, the better for them. Too many treats and fruit while well meant are actually having the opposite effect on your guinea pigs' health and longevity. With a good diet, you also don't have any need for artificial supplements as they are getting it all in their food.
Hay
Whether you feed timothy or meadow (UK)/orchard (US) hay doesn’t make a huge difference. Timothy hay is less high in calcium and is processed a little bit better in the guts, but it is harder and coarser in texture. Your piggies may like an occasional change or a mix of both, especially when the timothy hay is not looking very appetising!
Soft meadow/orchard hay is generally preferable for bedding/digging into and timothy hay for being fed from a hay rack in order to minimise the risk of eye injuries.
Alfalfa hay: alfalfa/lucerne is a legume, not a grass. It is high in calcium and protein and should only be fed as a supplement to normal hay during a pregnancy and the following nursing period (one handful per day to compensate for limited pellets before birth; see our pregnancy diet information thread at the top of the pregnancy section).
Young guinea pigs on alfalfa based pellets (which include most available brands) do NOT need any extra alfalfa hay!
Please do not feed hay that smells mouldy or fusty when you open a bag!
Do not feed or bed on straw. It is too rough as fodder and too dangerous as a bedding (high risk of eye pokes and skin scratches that can become infected).
Much more information on available varieties, a comparison chart of nutrients, lists of suppliers for the UK, US and Australia as well as tips for storage etc. in this comprehensive hay guide here: A Comprehensive Hay Guide for Guinea Pigs (incl. providers in several countries)
Grass
Fresh grass varies in quality over the course of a year, especially in its water and nutrient content.
For this reason fresh, fast growing green spring and autumn grass counts more towards your daily veg allowance (leave out some watery veg like lettuce or cucumber) while dry and brown grass that has stopped growing counts towards hay and you want to add more watery veg to your diet.
Please introduce fresh grass gradually on an unaccustomed gut and be careful to acclimatise your guinea pigs to the outdoors in order to avoid digestive problems and illness. Also do not feed very damp grass or clippings from the lawn.
Don't graze your guinea pigs in an area where dogs pee or get your grass from a verge that is used by lots of dog walkers. Fresh dog pee can kill a guinea pig!
More tips (including how long to wait after lawn treatment and when it is safe to put indoors guinea pigs on the lawn) in this guide here: Feeding Grass And Preparing Your Piggies For Lawn Time
Hot weather tips and information on heat stroke: Hot Weather Management, Heat Strokes and Fly Strike
You can always grow your own grass in a window sill box or a seed tray. Even if you haven't got access to safe grass, it makes a great treat and a wonderful enrichment for your piggies and it provides an additional healthy source of vitamin C.
2 Hay and fresh grass
3 Vegetables, fresh herbs and fruit with an illustrated balanced sample diet
4 Special dietary needs
- Urinary tract infections, bladder stones and sterile IC (non-bacterial interstitial cystitis)
- Diabetes and long term digestive problems
- Impaction in boars
- Pregnancy and nursing dietary tweaks (only visible to registered members who have accepted our no intentional breeding policy)
5 Common veg list: How much and how often?
6 Pellets
7 Water
8 Forage, seeds and treats- safe and unsafe
9 The life-saving importance of weighing weekly
10 Tips on how to save on your piggy food bill
11 Running out of certain foods? - Practical advice
Sadly for new guinea pig owners, we do not have the ultimate ideal guinea pig diet yet! New insights will lead to new recommendations and trends.
There is as yet not as much research into guinea pigs as into other pet species; so things are bound to change as more is becoming known. Currently there is a lot of contradictory information around which can be very confusing. We are trying to keep abreast of developments and also include our own practical positive experiences as we go along, so it is always worth to re-read this guide from time to time!
This thread is aiming to help you develop your own diet that is based on your guinea pigs’ individual tastes and preferences and the availability/practicalities of what you can buy, grow, store and use up within reason.
1 The recommended ratio of food groups
The diet on which guinea pigs have evolved on and for which their dental and digestive system is laid out for basically falls into just two categories - mainly grass fibre and some supplementary forage. This supplementary category has split into many different undergroups, so it is very easy to lose sight of diet as a whole. Far too many owners also fall into the traps of treating treats as a dietary non-entity.
Additionally, the hardness and mineral content of the local water also needs to be taken into account; even more so in a mainly hard water country like the UK.
The recommended food group ratio per piggy per day
1 ca. 75-80% hay and fresh grass (unlimited and refilled at least once a day, preferably more often)
2 ca. 20-25% original supplementary wild forage:
- ca. 15-20% preferably green veg, fresh forage and fresh herbs (ca. 1 cupful / 50g / nearly 2oz)
- ca. 5% pellets or dry forage (1 tablespoon)
- any treats, including alfalfa and rich hays, are coming out of this group budget!
3 fresh plain cool/drinkable water daily (calcium content needs to be factored into the overall diet)
You can tweak the calcium intake within the supplementary group by - for instance - dropping pellets altogether and/or by filtering water etc. in order to feed a bit more high calcium veg (which also contain vitamin C and otherwise not supplemented magnesium). Please do not try to eliminate calcium altogether; it is essential for long term health. There is a locally dependent soft spot in the diet, each side of which - too high or too low - you can get stones or crystals.
2 Hay and fresh grass
Unlimited fresh hay should make the bulk of a guinea pig diet. It is vital for good gut and general health and to keep the all-important grinding back teeth ground down evenly.
Guinea pigs have evolved by eating grass in its fresh and dried form with supplementing their diet with some forage and any rare fruit they come across. What most people are not aware of is that fresh growing grass is actually high in vitamin C and that even hay contains it, if not in high concentrations.
This is the reason why guinea pigs have never had the need to make their own vitamin C. Because hay and grass are not part of a human diet, this food group has been generally blended out and been treated as if it didn't contribute any nutrients to the overall diet. The opposite is in fact true - hay and fresh grass are by a very long margin the mainstay of the diet and should make around 80% or more of what a guinea pig eats in a day. This can really add another 1-2 years to a healthy guinea's life and take it from the bottom of the average life span to the higher end and beyond.
Please always offer unlimited hay to your guinea pigs at all times (even when they have access to the lawn); too much fresh feed can cause digestive problems. It is the one food group you really can't do without!
The more your diet resembles the natural diet of guinea pigs, the better for them. Too many treats and fruit while well meant are actually having the opposite effect on your guinea pigs' health and longevity. With a good diet, you also don't have any need for artificial supplements as they are getting it all in their food.
Hay
Whether you feed timothy or meadow (UK)/orchard (US) hay doesn’t make a huge difference. Timothy hay is less high in calcium and is processed a little bit better in the guts, but it is harder and coarser in texture. Your piggies may like an occasional change or a mix of both, especially when the timothy hay is not looking very appetising!
Soft meadow/orchard hay is generally preferable for bedding/digging into and timothy hay for being fed from a hay rack in order to minimise the risk of eye injuries.
Alfalfa hay: alfalfa/lucerne is a legume, not a grass. It is high in calcium and protein and should only be fed as a supplement to normal hay during a pregnancy and the following nursing period (one handful per day to compensate for limited pellets before birth; see our pregnancy diet information thread at the top of the pregnancy section).
Young guinea pigs on alfalfa based pellets (which include most available brands) do NOT need any extra alfalfa hay!
Please do not feed hay that smells mouldy or fusty when you open a bag!
Do not feed or bed on straw. It is too rough as fodder and too dangerous as a bedding (high risk of eye pokes and skin scratches that can become infected).
Much more information on available varieties, a comparison chart of nutrients, lists of suppliers for the UK, US and Australia as well as tips for storage etc. in this comprehensive hay guide here: A Comprehensive Hay Guide for Guinea Pigs (incl. providers in several countries)
Grass
Fresh grass varies in quality over the course of a year, especially in its water and nutrient content.
For this reason fresh, fast growing green spring and autumn grass counts more towards your daily veg allowance (leave out some watery veg like lettuce or cucumber) while dry and brown grass that has stopped growing counts towards hay and you want to add more watery veg to your diet.
Please introduce fresh grass gradually on an unaccustomed gut and be careful to acclimatise your guinea pigs to the outdoors in order to avoid digestive problems and illness. Also do not feed very damp grass or clippings from the lawn.
Don't graze your guinea pigs in an area where dogs pee or get your grass from a verge that is used by lots of dog walkers. Fresh dog pee can kill a guinea pig!
More tips (including how long to wait after lawn treatment and when it is safe to put indoors guinea pigs on the lawn) in this guide here: Feeding Grass And Preparing Your Piggies For Lawn Time
Hot weather tips and information on heat stroke: Hot Weather Management, Heat Strokes and Fly Strike
You can always grow your own grass in a window sill box or a seed tray. Even if you haven't got access to safe grass, it makes a great treat and a wonderful enrichment for your piggies and it provides an additional healthy source of vitamin C.