Supreme Science Selective Guinea Pig is a complete, balanced, sugar free, fiber rich feed for guinea pigs with alfalfa, dandelion, fennel and nettle. This composition contributes to an improved digestive system with less odds of blockages and it lowers the odds of bladder stones. Supreme Science Selective is a well mixed feed to prevent the guinea pig from selective eating so that it ingests all of the ingredients, including sufficient vitamin C. Guinea pigs are incapable of producing vitamin C themselves, so they need to be provided with supplements daily.