The three-part guinea pig diet: unlimited hay, a little pellet, fresh veg, and the vitamin C they cannot make.
Guinea pig diet is simple once you know the three parts, and getting it right prevents most of the health problems that land pigs at the vet.
Grass hay (Timothy, orchard or meadow) should make up about 80% of the diet and be available every hour of every day. It keeps their gut moving and wears down teeth that never stop growing. Buy it in bulk, this is the one thing you truly cannot skimp on: good Timothy hay.
About an eighth of a cup of plain, vitamin-C fortified guinea pig pellets per pig. Skip the colorful 'muesli' mixes with seeds and corn, pigs pick out the junk and leave the healthy bits.
A cup of fresh veg a day, mostly leafy greens: romaine, red and green leaf lettuce, cilantro, and a little bell pepper (high in vitamin C). Guinea pigs cannot make their own vitamin C, so daily fresh veg matters, and many owners add a small vitamin C supplement to be safe.
