We get asked this question a lot here at HayDay, and while it might seem obvious to some, it's a genuinely important one for any pet owner wanting to get their guinea pig's diet right.
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Overview: Guinea Pigs and Rabbit Food
Guinea pigs shouldn't eat rabbit food because it doesn't meet their nutritional needs, most notably missing the vitamin C that guinea pigs can't produce on their own. Feeding rabbit pellets to guinea pigs regularly can lead to serious health problems, including scurvy, malnutrition, and obesity, caused by an incomplete nutritional balance.
The ideal guinea pig diet includes unlimited high-quality hay, fresh water, guinea pig-specific pellets, and a daily handful of fresh greens and vegetables, particularly ones high in vitamin C.
What's the Difference Between Rabbit Food and Guinea Pig Food?
The main difference comes down to vitamin C and overall nutrient balance, not size or general food type. Rabbits can synthesise their own vitamin C internally, so rabbit food isn't formulated to include it, but guinea pigs can't produce this vitamin themselves and rely entirely on their diet to get enough.
Guinea pigs also absorb vitamin B12 through bacteria in their caecum, obtained partly by eating their own droppings (caecotrophy), a completely normal and essential digestive process. Rabbit pellets simply aren't designed around these specific biological needs.
What do rabbits and guinea pigs have in common?
Hay is where the overlap happens. Both species thrive on the same varieties, including Timothy and Meadow hay, which provide the fibre needed to support healthy digestion and wear down their continuously growing teeth.
How Do Guinea Pig and Rabbit Pellets Differ?
Guinea pig and rabbit pellets are each formulated for the specific needs of their respective species, and the differences go well beyond vitamin C.
Why Is Vitamin C So Important for Guinea Pigs?
Vitamin C plays a crucial role in guinea pig health, supporting healthy skin, joints, and mucosal surfaces. An adult, non-breeding guinea pig needs around 10mg/kg/day, and this requirement can rise during pregnancy, illness, or stress.
Fresh vegetables are a great way to top up vitamin C naturally. Dandelion greens contain around 35mg per 100g, while lettuce provides roughly 24mg per 100g, making both useful additions alongside a good-quality pellet.
What Is Scurvy in Guinea Pigs?
Scurvy is a serious condition caused by prolonged vitamin C deficiency, affecting blood vessels and overall health. Signs to watch for include:
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Poor coat condition
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Slow wound healing
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Reduced appetite
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Weight loss
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Lethargy
Guinea pigs fed rabbit pellets long-term are particularly at risk, and may go on to develop more advanced symptoms such as diarrhoea, a rough coat, swollen joints, or bleeding gums. If you suspect scurvy, contact a vet promptly for diagnosis and treatment.
How Much Protein and Fibre Do Guinea Pigs Need?
Guinea pigs need a specific balance of protein and fibre that differs from rabbits. Good-quality guinea pig pellets typically contain 16-20% crude protein, with a minimum energy content of 3.0 Mcal ME/kg (12.5 MJ ME/kg). Protein supports growth and general health, and a deficiency can lead to unexplained weight loss or signs of illness.
Fibre is equally important for healthy digestion, and rabbit food simply isn't formulated to meet these combined protein, fibre, and vitamin requirements for guinea pigs.
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How Much Fat Should Be in a Guinea Pig's Diet?
Guinea pigs need a carefully balanced, moderate amount of fat, and too much can lead to obesity, digestive problems, liver disease, or heart disease. Excess fat intake has also been linked to dyslipidemia, glucose intolerance, organ damage, lethargy, and weakness, along with more serious conditions like hepatic lipidosis, ketosis, and toxaemia.
Linoleic acid is one beneficial fat for guinea pigs and should make up around 1% of their daily calorie intake, supporting skin and coat health without tipping into excess.
Can Rabbit Food Cause Malnutrition in Guinea Pigs?
Yes, feeding guinea pigs rabbit food long-term can lead to malnutrition and reduced energy levels. Guinea pigs need around 16-18% protein in their diet, a requirement rabbit food generally doesn't meet, and insufficient protein forces their bodies to break down fat stores for energy instead.
While guinea pigs can often recover once switched to an appropriate diet, it's always best to get their nutrition right from the start rather than correcting problems later.
What Should Guinea Pigs Actually Eat?
A proper guinea pig diet includes high-quality pellets, unlimited hay, and a daily serving of vitamin C-rich fruit and vegetables such as:
Order high-quality, barn-dried hay for guinea pigs online now.
Why Are High-Quality Pellets Essential?
Guinea pig pellets form the nutritional backbone of their diet. Good-quality pellets should typically contain:
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Around 14.0% crude protein
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At least 2.0% crude fat
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At least 25.0% crude fibre
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At least 0.4% calcium
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Stabilised vitamin C and other essential vitamins and minerals
Why Is Unlimited Hay Non-Negotiable?
Hay should always be available in unlimited amounts, providing the high fibre content guinea pigs need for healthy digestion while wearing down their continuously growing teeth. Without enough hay, guinea pigs risk becoming overweight and developing dental or digestive problems.
Overgrown teeth or signs of GI stasis can indicate a guinea pig isn't getting enough hay, and it's always worth speaking to a vet if you notice either. Try our premium quality barn-dried hay, suitable for small pets - Click here now >
Which Vegetables Are Best for Boosting Vitamin C?
A rotating mix of vitamin C-rich vegetables helps guinea pigs meet their daily requirement naturally. Good options include:
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Kale (moderation)
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Parsnips
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Spinach (moderation)
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Bell peppers, particularly high in vitamin C
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Pak choi
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Watercress
For a full list of guinea pig-safe herbs, vegetables, and fruit, the PDSA website is a helpful additional resource.
Can Guinea Pigs and Rabbits Live Together?
Guinea pigs and rabbits can sometimes get along well as companions, but their differing dietary needs mean their food should never be shared or mixed. Even with friendly cohabitation, each pet should be fed separately according to their own species-specific requirements, with hay remaining an unlimited staple for both.
Getting a guinea pig's diet right comes down to consistency: high-quality pellets, unlimited hay, and a steady supply of vitamin C-rich vegetables. Regular weigh-ins are also worth building into your routine, as unexpected weight changes are often one of the earliest signs of an underlying health issue, and it's always worth checking in with a vet or nutritionist to stay up to date with current guinea pig care advice.
Frequently Asked Questions
Can I use rabbit hay for guinea pigs?
Yes, you can use rabbit hay for guinea pigs and other small animals, as they eat the same hay. Popular hay choices include Timothy hay, Meadow and/or Alfalfa Hay.
