Guinea pigs are popular pets for many reasons. They are docile and friendly, and once tamed, they seem to enjoy interaction with their owners. They make ideal first pets for older children, because they are easy to care for and rarely bite. A guinea pig does not require a lot of space, so it is an ideal pet for a child's bedroom or for a person living in an apartment. The guinea pig's life span of 3-5 years is longer than that of smaller rodents such as hamsters, gerbils, rats, and mice.

This handsome guinea pig demonstrates a picture of health. Notice the healthy body structure (not too fat, not too thin), the smooth, shiny hair coat and the discharge-free nostrils and eyes. Read on to learn how you can keep your pig in great shape.

Another name for the guinea pig is "cavy" from its scientific name, Cavia porcellus. Guinea pigs are rodents from South America, which were initially tamed by the Incas of Peru. The most common varieties of guinea pigs found in pet stores today are the English shorthaired, the Peruvian longhaired, and the Abyssinian rough-haired. Newer strains of longhaired cavies include the smooth-coated Silkies and the rough-haired Woolies. Many guinea pigs kept as pets are actually "mixed breeds." The various types of guinea pigs can be found in numerous colors and color combinations.

The guinea pig's long gestation period (length of pregnancy) of 59-72 days is similar to that of dogs and cats rather than the other members of the rodent family (e.g., rats, mice, hamsters, and gerbils) that typically have a 21-to-28 day gestation period. This longer period results in well-developed (precocial) offspring that have open eyes and full hair coats when born and eat solid food within several days. It is ideal to breed the female guinea pig before the age of 6 months. After that time pelvic structures fuse and giving birth may be more difficult.  Any guinea pig pregnancy warrants a visit to your veterinarian for an exam and discussion on birthing..

This baby guinea pig is just 3 hours old.! Notice how they are born fully developed and furred. Within several days newborn guinea pigs are already eating on their own and require very little nursing care from the mother pig. Guinea pigs also become sexually mature at an early age and it is suggested that males and females be separated or neutered by the time they are 12 weeks old in order to prevent reproduction

Caging should be large enough to accommodate food bowls and some "cage furniture," which can be as simple as a cardboard box and a piece of PVC tubing. This allows your pet to explore and find seclusion. Cage flooring should be solid metal or plastic, which is easy to clean. Avoid wire flooring that can be rough on the bottoms of guinea pigs' feet and can potentially catch their small feet and toenails. Guinea pigs are sensitive to overheating, and ammonia from urine can cause respiratory problems. For these reasons, it is important that the cage provide adequate ventilation and be cleaned at least twice weekly.

One way to make cage cleaning easier is to line the bottom with newspaper, then cover it with the desired bedding. Bedding can be shredded paper (avoid shiny ads that can contain toxic substances), hardwood shavings, or composite recycled newspaper pellets. Cedar and pine shavings are not recommended, because they contain resins that can be irritating to your guinea pigs' skin, eyes, and mucous membranes. Aspen shavings, such as Oxbow Pet Product's Aspen Fresh, is a preferred bedding material for your guinea pig. Hay can also be used as bedding

Recycled paper bedding such as Yesterdays News™ or Carefresh™ are bio-degradeable and tend to be non-irritating to the guinea pigs skin or respiratory tract. They are therefore suitable choices for the guinea pigs bedding.

Guinea pigs enjoy the opportunity to run outside the cage. Placing them on a vinyl floor makes cleanup easier and gives your guinea pig a chance for extended exercise. Guinea pigs also enjoy being outside in the grass, but they need to be closely supervised.

Fresh, clean water is a must for your pet guinea pig. A water bottle with a sipper tube works better than a water bowl, which can be tipped over or contaminated with waste and bedding. Hanging the water bowl on the outside of the cage so just the tip of the spout is inside discourages chewing of the sipper tube. Water needs to be changed daily, and the sipper tube should be cleaned weekly.

Guinea pigs are not able to produce their own vitamin C, a peculiarity they share with humans and other primates. The daily requirement of vitamin C for a guinea pig is 50 mg. 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. Converting to this highly palatable diet from another food source is usually simple, but a gradual conversion (1-2 weeks) is recommended. Pellets can be fed in a sturdy crock bowl, which should be cleaned daily. To ensure adequate levels of vitamin C, Oxbow's Xtra Tabs can be offered on a daily basis. 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. Avoid gas-forming vegetables such as broccoli or cauliflower.

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.

Free-choice grass hay is another essential part of your guinea pig's diet. Hay provides essential fiber, which helps maintain intestinal and dental health. The doctors at Pet Care Veterinary Hospital recommend you feed your guinea pig unlimited quantities of timothy, brome, orchard, or oat hay. Hay also helps prevent boredom by satisfying the guinea pig's innate desire to chew, which is an important means of dental health maintenance.

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 prone to dental problems such as malocclusion and molar spur formation. Improper wearing of teeth secondary to improper diet and a lack of suitable chewing materials can result in sharp points on the upper and lower molars, which can be painful to the cheek and tongue. A guinea pig with a dental problem will often have a depressed appetite, and food may drop from the mouth as the guinea pig attempts to chew. Irritation from molar spurs can also cause increased salivation and result in a wet, matted chin (slobbers). A visit to the vet is in order if you see these abnormal signs. Provide plenty of hay and blocks of wood for chewing to help prevent this painful condition.

This guinea pig skull shows how molars can overgrow and cause uncomfortable dental points. The overgrown upper molars (black arrow) rub against the inside cheek tissue and the overgrown lower molars (red arrow) entrap the tongue. Affected guinea pigs can show signs of excessive salivation or try to eat food but drop it from their mouths as the overgrown teeth do not allow for normal chewing.

This picture shows an anesthetized guinea pig with the overgrown lower molars as described above.  Extensive dental trimming and filing is necessary to try and return this pig to normal.

Bladder stone formation is relatively common in guinea pigs. These stones may form secondary to urinary tract infection, decreased water intake (sometimes as a result of adding vitamin C to the water), or an imbalanced of calcium and phosphorus in the diet. Imbalance dietary levels of vitamin D and magnesium may also contribute. Oxbow's Cavy Cuisine, made with timothy hay, is designed to provide the mature guinea pig with the nutritionally appropriate calcium: phosphorus ratio as well as appropriate levels of magnesium and vitamin D.

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.

Feeding Recommendations at a Glance:

Growing Guinea Pigs
Unlimited amounts of Cavy Performance along with free-choice grass hay
Mature Guinea Pigs
1/8 - 1/4 cup Cavy Cuisine daily along with free-choice grass hay
Gestating and Lactating Guinea Pigs
Unlimited amounts of Cavy Performance along with free-choice grass hay

Guinea Pig Facts

When frightened, guinea pigs may freeze in position or "stampede."
Guinea pigs originated in South America and are also known as cavies.
Guinea pigs can make a variety of noises including chatters, whines, squeals, purrs, whistles, screams, chirps, and grunts.
Life span 4-8 yrs (avg. 5 yrs)
Average adult male weight 900-1200 g (2-2.6 lb)
Average adult female weight 750-900 g (1.7-2 lb)
Gestation period 59-72 days (avg. 63 days)
Litter size 1-6
Optimal weaning age 14-21 days

References

Johnson-Delaney C: Guinea pigs. Exotic Companion Medicine Handbook, Lake Worth, FL, Zoological Education Network, 1996.
Hillyer EV, Quesenberry KE, Donnelly TM: Biology, husbandry, and clinical techniques [guinea p whiand chinchillas]. In: Quesenberry K, Hillyer E, eds: Ferrets, Rabbits, and Rodents: Clinical Medicine and Surgery. Philadelphia, PA, WB Saunders, 1997, pp 243-259.