Food and water must be readily available at all times. Commercially available pelleted chows provide all the essential nutrients, as long as the pellets are fresh and wholesome when offered. Some guinea pig owners are tempted to feed rabbit pellets, assuming that they are roughly equivalent to guinea pig pellets, but this is not so. Unlike most mammals (including rabbits), guinea pigs require a high level of the vitamin, folic acid. Unlike rabbits, guinea pigs cannot manufacture their own vitamin C and must, therefore, receive it from an outside source.


Interestingly, people and our primate relatives share this dependence on vitamin C from the food we consume. Pellets milled for guinea pigs take these special requirements into consideration and are appropriately fortified with these 2 nutrients, among many other essential ones. Guinea pig chows generally contain 18-20% protein, 16% fiber and about 1 gram of vitamin C per kilogram of ration. Even when the fresh pellets are properly stored in a cool, dry place, about half of the vitamin C content is degraded and lost within 6 weeks of manufacture.


Therefore, the diet should be supplemented with vitamin C as follows; 50 milligrams of ascorbic acid (such as human vitamin C syrup) should be added to 1 cup of drinking water, made up fresh every 12 hours. Alternately, one handful of fresh kale or cabbage or ¼ of an orange may be offered daily.


Any change in a guinea pig’s diet should be made gradually due to the animal’s sensitive digestive system. Guinea pigs tend to be creatures of habit and do not tolerate changes in the presentation of their food or water, nor change in the taste, odor, texture or form of the food itself. In fact, any sudden change in routine can result in the pet refusing its food and water, which can ultimately prove fatal.


All foods should be provided in heavy ceramic crocks. The crocks should be high enough to keep bedding and fecal pellets out of the food, but low enough for easy access by the animal. Water is most easily made available by the use of a water bottle equipped with a “sipper” tube. Guinea pigs tend to contaminate and clog their water bottles, therefore, clean and disinfect all food and water containers daily.