Guinea pig nutrition is built on a single critical fact: guinea pigs cannot synthesise Vitamin C. Like humans (and unlike most other mammals), guinea pigs lack the enzyme L-gulonolactone oxidase needed to produce ascorbic acid. Without daily dietary Vitamin C, they develop scurvy — a painful and potentially fatal condition causing swollen joints, lethargy, poor wound healing, and internal haemorrhaging. Every aspect of guinea pig diet planning revolves around this biological vulnerability.
The 80/10/10 Diet Ratio
- 80% Hay: Unlimited Timothy hay available at all times. Essential for dental wear (guinea pig teeth grow continuously) and gut motility. Without sufficient fibre, guinea pigs develop life-threatening gut stasis.
- 10% Pellets: One tablespoon (approximately one egg cup) of grass-based pellets per guinea pig per day. Provides concentrated Vitamin C and balanced minerals.
- 10% Fresh Vegetables: Approximately one cup of vegetables daily. Primary natural source of Vitamin C.
Quick Comparison: Best Guinea Pig Pellets UK 2026
| Product | Key Feature | Best For |
|---|---|---|
| Burgess Excel Nuggets | Added Vitamin C / Mint flavour | Overall best / Most available |
| Supreme Science Selective | High-fibre, vet-developed | Fussy eaters / Premium |
| Beaphar CARE+ | Dual-fibre technology | Digestive support |
⚠️ Avoid muesli-style mixes. Guinea pigs selectively eat the sugary, fatty components and leave the nutritious parts — the equivalent of a child eating only the marshmallows from a breakfast cereal. Single-component pellets (nuggets) prevent this selective feeding.
Safe & Unsafe Vegetables
| Daily (Safe) | 2-3x Weekly (Moderate) | ❌ NEVER |
|---|---|---|
| Bell peppers (esp. red) Romaine lettuce Cucumber Coriander/parsley |
Kale, spinach (high calcium) Broccoli (can bloat) Carrots (high sugar) Tomato (flesh only) |
Potato (all types) Onion/garlic Rhubarb Avocado Iceberg lettuce |
For housing your piggies, see Best Guinea Pig Hutch UK.
Part of our Guinea Pig Care Guide.
🥬 Recommended Guinea Pig Food
We’ve hand-picked these products for you. As an affiliate, we may earn a commission if you purchase through our links, at no extra cost to you.
Advertisement – affiliate links: Petz earns a commission from qualifying purchases made through these links, at no extra cost to you.