Guinea Pigs PDF Print E-mail

About Guinea Pigs

Basic Information


Guinea pigs, also known as cavies, are rodents native to the Andes Mountain area of South America. They were domesticated in South America by 500 AD, and possibly as early as 1000 BC, by the Incas who raised them for food and for use in religious ceremonies. Guinea pigs were brought to Europe during the 1500s where they were selectively bred as pets and laboratory animals.


Four primary varieties are commonly encountered in the pet industry. The Shorthair or English has a uniformly short hair coat. The Abyssinian has whorls or rosettes in a short, wiry coat. The Peruvian has very long, silky hair. The Silky is a large variety with medium length silky hair.

Life Span

Average 5-6 years.


Guinea pigs are lively, gentle and responsive pets, particularly if handled frequently at a young age. Their typical response to perceived danger is “freeze or flight,” tending to become very still when frightened or, alternatively, to make an explosive attempt at escape. However, they are rarely aggressive. Guinea pigs do not tolerate sudden changes in diet or environment. Their food preferences are established early in life, and they often refuse to eat if their food is changed in type or presentation, a condition, which can be potentially life threatening.


Eating Feces: Guinea pigs perform coprophagy, or cecotrophy, about 150 to 200 times per day. This is a normal part of maintaining a healthy digestive tract, and animals that are unable to eat the soft, cecal feces directly from the rectum will lose weight, fail to thrive, and are prone to fecal impaction. Obese or pregnant animals that cannot reach their rectum need to have access to the cecal feces on the floor of the cage. Therefore wire bottom cages that allow feces to fall out of reach are not appropriate in these animals.



Minimum size for a single Guinea pig is 30”(L)x18”(W)x12”(H), but larger cages are strongly recommended. Larger cages allow for adequate exercise and mental stimulation. For instructions on how to build a cage that is spacious, inexpensive and easy to clean, please visit the website Solid-sided enclosures, such as glass aquariums, should not be used due to poor ventilation. Placing the cage into a shallow cardboard box with the sides cut to a height of 5” can reduce the amount of debris scattered out the sides of the cage.


Cages are available commercially with either solid or wire mesh flooring. Wire mesh flooring can result in injuries to the feet and legs. Housing on wire over long periods of time can result in footpad infections, and broken legs are common in Guinea pigs that fall through the wire mesh and panic to escape. For these reasons, solid flooring is recommended, or at a minimum, wire mesh floors should have a solid platform as a resting place in one area of the cage.


Recycled paper bedding (CareFresh) is the best choice for bedding. Aspen wood shavings, shredded paper, and pelleted recycled newspaper are also acceptable beddings. Cedar and pine shavings should not be used, as they have been shown to cause respiratory and liver disease in Guinea pigs. Corncob beddings are available but may contain fungal spores that can potentially cause disease, and should be avoided. Bedding should be changed completely once a week, and any obviously wet spots removed daily.

Hide Box

Guinea pigs must be provided with some sort of dark shelter in the cage. Many varieties are commercially available, but a small cardboard box with a hole cut for entry works well in most cases. This allows your pet a “safe” place to hide when it is stressed.

Food Dishes

Dishes should be made of heavy ceramic to avoid spilling, and must be cleaned daily, as Guinea pigs tend to defecate in them.

Cage Location

The cage should be placed in a quiet area away from direct sunlight. Recommended temperature range is 60-75F. Guinea pigs tolerate cool temperatures better than heat, and are easily over heated (prone to heat stroke).


Dietary Preferences

Guinea pigs establish strong dietary preferences early in life. Changes in diet must be made very gradually to avoid a refusal to eat. It is a good idea to get Guinea pigs accustomed to a variety of foods (pellets, hay and fresh vegetables) early in life.


A wide variety of commercial pellets formulated specifically for Guinea pigs are available. Rabbit pellets are not an acceptable substitute, as they may contain toxic levels of vitamin D and are deficient in vitamin C and folic acid. Guinea pig pellets should be used within 90 days of the milling date (on the package), to maximize the amount of vitamin C, which degrades with time. Guinea pigs fed exclusively pellets are often malnourished due to insufficient fiber and vitamin C in the diet. Obesity is a common problem in mature pigs, and pellet intake should be restricted to 1/8-cup pellets per 2 pounds of Guinea pig per day. Young, growing, or pregnant Guinea pigs should eat alfalfa-based pellets, while Timothy-based pellets (Oxbow or Kaytee brand) are more appropriate for adults.


Fresh, clean grass or timothy hay should be available at all times. Alfalfa hay should not be given on a regular basis due to high levels of calcium that can lead to urinary tract disease. The fiber present in hay is important for maintaining a healthy gastrointestinal tract, and the abrasiveness helps to wear down the continuously growing cheek teeth.

Fresh Vegetables

Guinea pigs are unable to synthesize vitamin C, and therefore must eat foods rich in vitamin C to meet their requirements. The best way to meet this requirement is daily feeding of fresh, washed vegetables high in vitamin C. Foods that contain high levels of vitamin C include leafy greens (kale, romaine lettuce, mustard and collard greens, dandelion greens, spinach), red and green pepper, broccoli, kiwis and oranges. Fresh food should be offered daily (1/2 to 1 cup chopped) and the uneaten portion removed within several hours to prevent bacterial contamination.

Vitamin C

As noted above, Guinea pigs are unable to synthesize vitamin C. Although the best way to meet the requirement for vitamin C is by feeding fresh foods containing the nutrient, occasionally additional supplementation is warranted (e.g. a pig that refuses to eat fresh veggies-persistence usually pays of, so keep offering them!). Supplementation in the water can be attempted as follows: 100 mg ascorbic acid (human vitamin C tablets or syrup) added to 1 cup drinking water, made up fresh every 12 hours. However, supplementing vitamin C in the water is not very effective due to the rapid breakdown of the vitamin when exposed to light and heat, and the potentially bitter taste of some products. When attempting to supplement vitamin C in the water, fresh water without vitamin C should be offered several times a day to avoid dehydration that can result from the animal refusing to drink. The best way to supplement vitamin C is by using a chewable tablet (manufactured by Oxbow). Give 1 tablet daily per adult pig.


Clean, fresh water should be available at all times. Water bottles with sipper tubes help decrease the mess associated with tipped water bowls. However, many pigs will play with the sipper tube and even plug the end with partially chewed pellets. Therefore, daily cleaning of the bottle and tube with hot, soapy water is warranted. Soggy bedding from spilled water should be removed daily to prevent bacterial and fungal growth. Placing a corner litter pan containing pelleted newspaper litter (Yesterday’s news) beneath the water bottle sipper tube will help catch any drips and can be changed out as needed (usually every other day).

Litter Training

Most Guinea pigs will not ever become fully litter trained. However, placing litter pans in the cage corners that are used most for elimination can help tremendously in keeping the cage clean between full weekly bedding changes.


Remember: There's no need to breed!

Sexual Maturity

1) Female (sow): Females reach sexual maturity as early as 2 months of age and may be capable of reproducing up to 5 years of age. However, peak reproductive time for females is between 3 or 4 months to 20 months of age. The most important consideration regarding Guinea pig breeding is that the female (sow) must be bred prior to 6 months of age if she is to be bred at all. This is because the pelvis of the guinea pig fuses at an early age and will narrow the birth canal causing problems with delivery. Early breeding will prevent this fusion from occurring.

2) Male (boar): Males reach sexual maturity at 3 months of age, but it is best to wait until 4 months of age before breeding.

Estrous Cycle

Guinea pigs are polyestrous (multiple heat cycles) and breed year round in captivity. The heat cycle lasts 14-19 days, with a period of 12-15 hours during which the sow is receptive to the boar. Sows often go into heat a few hours after giving birth (i.e. postpartum estrus), and may be pregnant with another litter while still nursing.

Copulatory Plug

Copulation (breeding) in Guinea pigs can be confirmed by the finding of a copulatory or vaginal plug. This is a solid mass of coagulated ejaculate that can be observed in the vagina of the female directly after copulation and falls out within several hours. Current theory suggests that the primary function of the copulatory plug is to prevent another male from breeding the female once the initial copulation has occurred.


Range 60-72 days, average=68 days. This is relatively long when compared to most other rodents, and results in “precocial” young. This means that the pups are born relatively more developed than in other species (i.e. eyes are open, teeth erupted, fully furred, able to stand, able to eat some solid food). The sow will have a grossly distended abdomen in the later stages of pregnancy, and may double in weight. Several days prior to delivery, a widening of the pelvis region becomes noticeable as the pubic bones separate to enlarge the birth canal (this is the process that cannot occur in older sows that have not been previously bred and can lead to difficulties with delivery).

Litter Size

Range is 1-6; average=3.


An uncomplicated delivery usually takes about 30 minutes with 3-5 minutes between births. Any signs of straining without delivery of a pup may indicate problems with delivery (dystocia), particularly if the sow was bred later than 6 months of age. Call your veterinarian immediately if you are concerned that your sow’s delivery is not progressing normally, as medical intervention and surgery may be necessary. Abortions and stillbirths are fairly common, especially with sows bred for the first time. Sows will typically eat the placenta after delivery (this is a normal behavior and should be allowed to occur).


Pups need a minimum of 5 days of nursing and ideally should be weaned around 3 weeks of age. Pups that do not receive the sow’s milk the first 3-4 days of life usually do not survive. Sows are not typically very “motherly” and do not seek out the young to nurse them, but rather stands passively allowing them to nurse when they seek her out.

Medical Care

Physical Exam

The first exam should take place ideally soon after purchase. The exam will include discussion of diet and husbandry, as well as identifying any existing health problems. It is not uncommon for newly purchased female Guinea pigs to be pregnant, which also may be revealed on examination. Exams should be performed on an annual to semi-annual basis depending on the age and condition of the individual animal.

Dental Care

Guinea pigs have continuously growing teeth (both incisors and cheek teeth), and require high amounts of dietary fiber (hay is ideal) to keep these teeth ground down to normal levels. Some pigs are genetically predisposed to malocclusion (improper alignment and wearing of the teeth) and therefore should not be bred. The teeth should be examined at least annually, more often if drooling, reluctance to eat or dropping food from the mouth are noted. Overgrown teeth generally require general anesthesia to allow trimming and filing.

Intestinal Parasites

A fecal examination should be performed at the initial visit, and then on an as needed basis depending on the condition of the individual animal.


Weekly brushing with a soft bristle brush helps keep the skin and coat healthy, and reduces shedding. Most Guinea pigs love to be brushed! Nails need to be trimmed monthly. Bathing is rarely needed or indicated for healthy Guinea pigs.


Flea powders labeled for use in cats can be used safely on Guinea pigs. Other products may also be recommended by your veterinarian.

Getting Ready

Shopping List



Plastic Igloo


Ceramic Food Dishes


Large Water Bottle


Corner Litter Pan


Timothy Hay




Fresh Food


Vitamin C Tablets


Soft Bristle Brush


Nail Trimmers


Additional Items


Hanging wooden bird toy with a bell; cardboard boxes, paper bags, untreated wooden spoons, untreated wicker baskets, some hard plastic cat toys, stuffed animals--be careful he doesn't eat the stuffing!


Fleece lined small animal bed or small oval cat bed pinned together to make a 'taco.'

Additional Hiding Places

Wooden hide box, grass hut, cardboard boxes with holes, plastic step stool, etc

Play Pen


Hay Container

Untreated wicker baskets, paper bags, and empty cardboard food boxes to put hay in.


- 1/8-1/4 cup pellets (timothy-based) - Free choice hay (he should never run out!) - One vitamin C tablet (put in dish on top of pellets) - 1 cup fresh salad (base of leafy greens--kale, romaine, parsley, mustard or collard greens, etc; plus small amounts of other low starch veggies--cucumber, bell peppers-all colors, pea pods, broccoli, etc; very small amounts of fruit--apple, berries, kiwi, mango, pear, etc.) - One orange wedge (about 1/6 of a medium-sized orange) - Fresh water (refill the bottle with fresh water every day or two; thoroughly scrub the bottle, sipper tube and rubber ring once a week in hot, soapy water)

We really recommend the Oxbow brand pellets, hay and vitamin C tablets. You can purchase these locally at Animall ( located in the Prime Outlets of Morrisville (at the airport mall), or at Phydeaux in Carrboro; or you can order directly from the company ( The quality of the nutrition is far superior to what you will find at the larger chain pet stores, and worth the extra effort. Kaytee Timothy Complete is the only timothy based pellet you can find at PetSmart or Petco. All of the other brands are alfalfa based, which is not appropriate for adult pigs.



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