Hides and houses
Shelves and ledges
Foraging and toys
Cage accessories
Kits and bundles
Fairy forest
Spooky mischief
Sweetie stash
Game mode
Forest floor
Castles and cathedrals
No, guinea pigs should not eat walnuts. Burgess says all nuts are high in fat, not fibre, and give guinea pigs extremely uncomfortable indigestion, and VCA tells owners not to feed nuts at all. A piece of walnut can also be swallowed whole and choke a small animal. A crumb is unlikely to cause harm, but more than that means watching closely and ringing your vet if anything changes.
| Safe? | No |
| How much | None |
| How often | Never |
| Best served | Not at all. Offer hay or fresh herbs instead |
| Watch out for | Shells, nut mixes, walnut cake and biscuits |
Why can't guinea pigs eat walnuts?
A guinea pig's gut is made for a steady stream of fibre. The PDSA says hay and grass should make up 85 to 90% of what they eat. Walnuts, like other nuts, are rich in fat and offer nothing a guinea pig needs. No vet source we use has a page on walnuts alone, so we've applied what they say about nuts in general, which is clear:
- Burgess: all nuts are high in fat, not fibre, and cause extremely uncomfortable indigestion.
- VCA: don't feed guinea pigs seeds or nuts, as they are too high in carbohydrates and fat.
- Guinea Lynx: avoid mixes or treats with nuts, seeds, dried fruit and dyed pieces.
The Vet Desk's vet-reviewed advice on peanuts adds a choking risk from whole nuts and a fungal toxin risk from shells and husks. We'd apply both to walnuts too.
Are any walnut foods safe?
No. Raw, roasted, candied, pickled and chopped walnuts are all a no, as are walnut shells, walnut oil and baked goods such as coffee and walnut cake or banana bread with walnuts. Nuts that have gone off or look damp and discoloured are worse still. Check treat sticks and muesli-style mixes, which sometimes contain nut pieces; the PDSA advises plain grass-based pellets instead.
My guinea pig ate some walnut. What should I do?
- Clear it away. Pick up every piece of nut and shell from the cage or play area.
- Judge the amount. A crumb is very unlikely to matter. If your guinea pig ate a whole half, several pieces or any shell, ring your vet now for advice, as the Vet Desk advises for peanut shells.
- Keep hay and water topped up. Hay keeps the gut moving. Don't try home remedies.
- Watch for a day. Check appetite and droppings. Small, few or runny droppings, or a guinea pig that won't eat, mean a call to the vet.
A guinea pig that stops eating needs a vet the same day. The PDSA says to contact your vet as soon as possible if a guinea pig stops eating or has severe diarrhoea, because stomach upsets can quickly become very serious.
Who is most at risk?
All guinea pigs should avoid walnuts. Babies, older guinea pigs and any with dental problems or a sensitive stomach are most at risk of choking or a bad upset, so ring your vet sooner for them.
What to give instead
For a treat to hand-feed, use a sprig of coriander (cilantro) or parsley, a strip of pepper or a cube of raw pumpkin. Other nuts are a no as well: see peanuts and almonds. Our safe food list, guinea pig diet guide and guinea pig care guide have everything else.
Walnut questions
Are walnuts poisonous to guinea pigs?
Our sources don't single out walnuts as poisonous, but every one we use rules out nuts for guinea pigs. Burgess says all nuts are high in fat, not fibre, and cause extremely uncomfortable indigestion, and VCA says not to feed nuts at all. So the answer is a firm no either way.
Can guinea pigs chew walnut shells?
No. Our sources don't cover walnut shells directly, so we reason from what they say about peanuts: the Vet Desk warns that peanut shells and husks can carry aflatoxin, a fungal toxin, and we'd treat walnut shells the same way. They are also hard and break into sharp pieces. Give hay and safe chews instead.
What if my guinea pig ate a tiny crumb of walnut?
A crumb is very unlikely to cause harm. Take away the rest, keep hay and water topped up and watch appetite and droppings for a day. If your guinea pig stops eating, or droppings get smaller, stop or go runny, ring your vet, as the PDSA advises.
Can guinea pigs eat walnut tree leaves?
We wouldn't offer them. None of the welfare or vet sources we use list walnut leaves or branches as safe for guinea pigs, and when a plant isn't on a trusted safe list the careful choice is to leave it out. Fresh grass and safe herbs are better forage.
