Guinea pigs can't make their own vitamin C the way most other rodents can, which is why a guinea pig food needs it added directly rather than relying on the animal to produce it — a detail that's easy to miss if you assume all small-animal mixes are interchangeable.

Gerty Guinea Pig Tasty Mix is built from extruded wheat, flaked peas, flaked maize, alfalfa meal, soya bean meal, flaked wheat, whole oats, soya bean hulls, extruded maize, soya oil, wheat feed and extruded locust beans, with vitamin C added at 250mg/kg. Supreme's own guide is 40-50g a day for an average adult guinea pig, alongside fresh vegetables, hay and water.

• Vitamin C added at 250mg/kg
• Protein 16%, crude fibre 8%, fat content 4%
• Inorganic matter 5%, calcium 0.6%, phosphorus 0.5%
• Feeding guide: 40-50g per guinea pig per day
• 850g, 5kg or 12.5kg bag

On the vitamin C. The added 250mg/kg matters specifically because guinea pigs, unlike most small pets, need vitamin C from their diet rather than making it themselves — worth checking any other food or treats you're feeding also account for this, rather than assuming it's covered automatically.

Who it's for: guinea pig owners who want a mixed food that specifically accounts for their pet's vitamin C needs, alongside fresh vegetables and hay.