Guinea pigs are well-developed at birth and within a few months are able to eat an adult diet. Guinea pigs are strict herbivores, and like rabbits are hind-gut fermentors that practice coprophagy (ingestion of ones own feces).

Coprophagy may be a source of B vitamins and a means of optimizing protein utilization, however its precise contribution to the nutritional needs of guinea pigs is not fully known. As hind-gut fermentors, guinea pigs digest much of their food in the cecum and colon (large intestine) which are at the end of the digestive tract. The cecum, a large thin-walled sac located at the junction of the small and large intestine, contains up to 65 percent of gastrointestinal (GI) contents. Within the cecum, bacteria and protozoa aid digestion of foods taken in by the guinea pig. Fiber is needed for these bacteria and protozoa to stay in balance and function properly. Fiber also aids in maintaining normal GI motility. Without fiber the gastrointestinal tract slows down, resulting in subsequent changes in the cecum pH, fermentation, and bacterial population. With time these changes in the intestinal tract environment can lead to indigestion.

You can provide this essential fiber by feeding your guinea pig free-choice grass hay. The doctors at Pet Care Veterinary Hospital recommed you feed your guinea pig unlimited quantities of timothy, brome, orchard, or oat hay. Hay also helps prevent boredom by satisfying the guinea pigs innate desire to chew, which is an important means of dental health maintenance. As well, Oxbow's Cavy Cuisine is a high-fiber pelleted diet containing stabilized vitamin C and was designed to meet the specific nutritional needs of your guinea pig.

Vegetables with a high vitamin C content can also be offered; these include turnip, mustard, dandelion, and collard greens as well as kale. Your guinea pig can be offered up to 1 cup of these vegetables daily after items have been gradually introduced and the amounts slowly increased.

Pet Care Veterinary Hospital recommends the Oxbow Pet Product line of guinea pig foods, supplements and hay. Feeding two ounces of the Oxbow Cavy Cuisine per pig daily provides essential vitamins and nutrients including adequate amounts of Vitamin C. Feeding timothy hay free-choice (as much as they want all day long) gives guinea pigs the roughage they need to keep their intestinal tract healthy

The fiber guinea pigs need for nutrition, proper digestion and to aid in normal dental wear comes from feeding grass hays. Variety is the spice of life and that includes the hay you feed your guinea pig. Oxbow Pet Products offers a variety of hays and Pet Care Veterinary Hospital recommends the timothy, orchard grass, oat or botanical hays for the adult guinea pig. Botanical hay, Oxbow's newest variety, is a timothy hay with added dried herbs for flavor.

Guinea pigs are becoming a more valued, loved, and cared for pet in the eyes of their owners and as a result veterinary care for guinea pigs has increased. Those veterinarians seeing guinea pigs are noticing several health problems attributed to nutrition: vitamin C deficiency, gastrointestinal ileus, obesity, enteritis, and urolithiasis.

Signs of Vitamin C deficiency (scurvy) include hindleg weakness, gum inflammation, unkempt fur coat and sometimes bleeding in the joints or under the skin. Like humans, guinea pigs are unable to produce their own vitamin C and require a dietary source. Reported daily requirements of vitamin C range from 20-50 mg per kg of body weight per day. In order to prevent vitamin C deficiency and subsequent scurvy, Oxbow recommends feeding your guinea pig Cavy Cuisine, a pellet diet containing stabilized vitamin C. In addition, offering one of Oxbow's 50 mg Xtra C tabs on a daily basis will ensure your guinea pig is receiving all the vitamin C it needs.

Gastrointestinal ileus (malfunction of the digestive tract due to gut slowdown problems) is commonly seen in guinea pigs on low fiber diets. Many times pet owners do not notice the signs associated with gastrointestinal slowdown until it is too late. Decreased appetite, a bloated or tense abdomen, along with lethargy and a decrease in the volume and size of feces passed are all signs of gastrointestinal ileus. Diets that incorporate high levels of indisgestible fiber, in the form of free-choice grass hay, promote increased gut motility and thereby prevent this gut slowdown. Oxbow's Cavy Cuisine is made from a mature, first cutting timothy hay that provides the indigestible fiber needed for healthy digestive system function.

This x-ray of a guinea pig laying on its back shows evidence of increased gas in the intestinal tract (dark areas pointed out by arrows). This gas is the result of gastrointestinal slowdown, also known as GI stasis, and is quite painful. Guinea pigs with GI stasis will be off their food, have very small sized or no stools at all, and be quiet and inactive. Pigs in this condition are a medical emergency

Obesity in guinea pigs can lead to respiratory, heart, and liver disease. Typical guinea pig feeds on the market contain high levels of fat, commonly over 3 percent and as high as 5 percent. These feeds contain corn, oats and other grains that are designed to appeal to the consumer, but raise the starch and energy content of the food. Obesity not only leads to the previously mentioned health problems, but can also prevent coprophagy, which is necessary for the maintenance of normal gastrointestinal health. Cavy Cuisine was designed to prevent obesity by adding sufficient fiber to aid in overall digestion and eliminating those grains that raise fat content.

This guinea pig is overweight! Obesity in guinea pigs is most commonly the result of feeding too many pellets and not enough hay or greens. Feeding your pig as outlined is this article will go a long way in preventing many of the common health problems we see in guinea pigs on a daily basis.
Photo Courtesy of Teresa Bradley Baines, DVM

The minimum fiber level of Cavy Cuisine is 25 percent and the maximum is 28 percent thus providing a healthy balance of fiber and energy.
Enteritis, intestinal inflammation associated with toxin production, is a problem commonly associated with diets that contain high levels of energy (starch and glucose). A low fiber, high starch diet promotes gut hypomotility and changes the intestinal environmental pH that allows pathogens (bad bacteria) to produce toxins that can kill a guinea pig. The guinea pig with enteritis may have soft stools and be hunched and inactive due to increased GI gas production and the resulting abdominal pain. High fiber, low starch Cavy Cuisine is formulated to prevent enteritis.

Urolithiasis (bladder stones) is being seen in more and more guinea pigs and although many are secondary to urinary tract infections, a certain percentage of stones are caused by an imbalance of calcium and phosphorus in the diet. Forage feed, the natural diet for a wild guinea pig, has a higher calcium to phosphorus ratio. Grains have the inverse relationship and contain more phosphorus than calcium. Research has proven that diets that contain an inverse ratio of calcium and phosphorus can cause stones and soft tissue calcifications. Dietary levels of vitamin D and magnesium may also influence the development of bladder stones. Cavy Cuisine is designed to provide the mature guinea pig with the nutritionally proper calcium to phosphorus ratio and appropriate levels of Vitamin D and magnesium.

This x-ray of a guinea pig laying on its side shows evidence of a bladder stone (arrow). Guinea pigs with bladder stones may show evidence of blood in their urine, have a decreased appetite and often are hunched up and act like they are in pain. This second photo shows the actual stone during surgical removal.

Nutritionists and veterinarians agree that less nutrient dense diets are needed to prolong the lives of small mammals, specifically guinea pigs and rabbits. Cavy Cuisine is specifically designed to meet the maintenance nutritional needs of the adult guinea pig. The first ingredient in Cavy Cuisine is timothy hay, which veterinarians recommend for improving the nutritional health of guinea pigs through the better control of calcium and magnesium levels, the stimulation of normal gastrointestinal motility and the prevention of obesity. Through the science of nutrition, Oxbow Pet Products wants to provide adult guinea pigs an opportunity to live longer and healthier lives. As a result, Pet Care Veterinary Hospital endorses their products.

Dawn Hromanik-Nutritional Consultant, Oxbow Pet Products
Peter G. Fisher, DVM, Pet Care Veterinary Hospital

References

Hillyer EV, Quesenberry KE, Donnelly TM: Biology, husbandry, and clinical techniques [guinea pigs and chinchillas]. In Quesenberry K, Hillyer E, eds: Ferrets, Rabbits, and Rodents: Clinical Medicine and Surgery. Philadelphia, PA, WB Saunders, 1997, pp243-259.
Kupersmith D: A practical overview of small mammal nutrition, Seminars in Avian and Exotic Pet Medicine, Vol 7, no 3, WB Saunders, 1998: pp 141-147.