By Dr Duncan Houston
Plant-eating pets do not all need the same bowl of food. A rabbit, guinea pig and chinchilla share a need for suitable fibre, but copying one animal’s vegetable and pellet plan to another can cause trouble.
Build the diet around the species before adjusting for age, weight and health.
Quick Answer
Rabbits, guinea pigs and chinchillas need continuous access to suitable hay and fresh water, with an appropriate measured formulated food. Rabbits and guinea pigs also commonly receive suitable fresh greens; guinea pigs specifically require dietary vitamin C. Chinchilla feeding is more restrictive, so do not apply a large fresh-vegetable or fruit allowance to all herbivores.
What hay contributes
Grass hay offers long fibrous material, repeated chewing and opportunities to forage. Choose fresh, clean, dry hay and discard mouldy or heavily soiled portions. Timothy, orchard grass and suitable meadow hay are common adult options.
Lucerne, also called alfalfa, has a different nutrient profile and may be useful for particular life stages or clinical needs. It should not be substituted blindly for an adult grass-hay plan. A food’s suitability depends on the whole ration.
Compare the three feeding plans
| Species | Alongside hay | Key distinction |
|---|---|---|
| Rabbit | Measured rabbit pellets and gradually introduced suitable leafy foods | Avoid muesli feeding and excessive concentrated food. |
| Guinea pig | Guinea pig pellets and suitable vegetables, including reliable vitamin C sources | Rabbit food is not an equivalent vitamin C source. |
| Chinchilla | Measured chinchilla pellets and a conservative species-specific extras plan | Do not routinely feed a fruit-and-vegetable menu designed for rabbits. |
For species-specific detail, see the RSPCA rabbit feeding advice, North Carolina State University guinea pig guidance and PDSA chinchilla diet advice.
Why a universal percentage chart is unreliable
Wet greens, dry pellets and hay cannot be compared meaningfully without knowing whether a percentage describes volume, food weight, dry matter or calories. Intake also varies with size, life stage and disease.
Use the relevant species guidance and a measured pellet allowance, then assess weight, body condition and hay eating. Do not restrict hay to fit an arbitrary percentage.
A daily feeding check
- Refresh hay and remove wet or dirty portions.
- Check drinking water and the flow of any bottle nozzle.
- Measure the formulated ration and observe each animal eating.
- Offer appropriate fresh foods where suitable, introducing changes gradually.
- Check droppings, activity and any food being left behind.
Weigh regularly and record the result. In a group, stable total food consumption can hide one animal losing weight.
What does a feeding problem look like?
Weight gain may reflect excess pellets or treats. Weight loss, food falling from the mouth or refusal of coarse hay suggests more than a portion issue. Dental disease, pain, stress and systemic illness can all reduce intake.
When is this an emergency?
Contact an experienced vet urgently if a rabbit, guinea pig or chinchilla eats markedly less or its droppings diminish. A painful swollen abdomen, collapse, severe weakness or breathing difficulty requires emergency care. Do not try to correct a sick animal with fruit, oil or unprescribed gut medicines.
Common mistakes
- Assuming all herbivores can share pellets.
- Using hay as bedding but not checking whether it is eaten.
- Replacing food with sugary treats when appetite drops.
- Making abrupt changes to several dietary components.
Support healthy feeding beyond the bowl
Offer several accessible feeding points, safe exercise and simple forage opportunities. Provide compatible companionship where appropriate and enough hiding spaces to reduce competition. Keep routines predictable while monitoring individual animals.
Frequently asked questions
Can hay alone supply every nutrient?
Do not assume so. The complete plan must meet the species’ needs, including vitamin C for guinea pigs.
Do all three need fruit?
No. Fruit is unnecessary and sugary extras are particularly inappropriate for routine chinchilla feeding.
Can good hay prevent every dental problem?
No. It supports normal chewing, but genetics, injury and existing disease can still require treatment.
Are younger animals fed like adults?
Not always. Growth, pregnancy and nursing require an individual life-stage plan.
The common foundation is fibre, water and observation. The details belong to the species, not a single generic herbivore recipe.
For help making sense of your animal’s care needs, explore ASK A VET™. Contact your veterinarian directly for urgent concerns.
The ASK A VET™ Tracker logs live location and activity trends, so a change in routine never goes unnoticed.
- Chinchillas
- Guinea Pigs
- Herbivores
- Rabbits
- Small Pet Nutrition

Every ASK A VET article is written and reviewed by qualified veterinarians.

