Guinea Pig

The guinea pig is a docile rodent native to the Andes Mountain region of South America . First domesticated by the Andean Indians of Peru, guinea pigs were used as a food source and as a sacrificial offering to the Incan gods. During the 16th Century, Dutch explorers introduced guinea pigs to Europe , where fanciers selectively bred them. Because of their docile nature and clean and quiet behavior, guinea pigs are popular pets.

There are eight varieties of guinea pigs they include the American, Abyssinian, Coronet, Peruvian, Silkie, Teddy, Texel , and White Crested.


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.


Adequate housing is a major factor in the maintenance of healthy pets. Guinea pigs can be housed within enclosures made of wire, stainless steel, durable plastic, or glass. The latter three materials are preferred since they resist corrosion. Wood should not be used due to difficulty in cleaning and susceptibility to destructive gnawing. Ideally, the enclosure should have an open side for adequate ventilation, so be careful when using aquariums. In addition, the cage must be free of sharp edges and other potential hazards. The enclosure size should allow for normal guinea pig activity. Approximately 100 square inches of floor area per adult guinea pig is recommended.

Bedding material must be clean, nontoxic, absorbent, relatively dust-free and easy to replace. Products like CAREFRESH pet bedding, commercial pellets, recycled newspaper, and processed ground corncob work well. Sawdust should be avoided because it tends to collect within the external genitalia of males. Cedar shavings have been associated with causing respiratory difficulty and liver disease in some guinea pigs, so should not be used.


Generally, guinea pigs are non-aggressive animals that rarely bite or scratch when handled. Instead, they may typically voice their protest with a high-pitched squeal. When handling, place one hand under the guinea pig’s chest and abdomen, while the other hand supports the hindquarters.


The single most important consideration regarding guinea pig breeding is that the female guinea pig (sow) should be bred between four and seven months of age if she is to be bred at all. The pelvis (birth canal) of the guinea pig fuses after seven months of age in the female guinea pig, thus preventing the babies from passing easily. Breeding a virgin sow after she is seven months old commonly results in very serious and often fatal problems with delivery. Males (boars) should be at least four months of age before breeding.

The sow’s estrous cycle lasts 14-19 days. The actual period in which the sow is receptive to the boar for breeding is approximately 8-15 hours during this cycle. Slows often return to “heat” within a few hours after giving birth. Pregnancy lasts between 63-70 days. Pregnant sows exhibit a grossly enlarged abdomen during the later stages of pregnancy. An uncomplicated delivery usually takes about ½ hour with an average of five minutes between babies. Litter size range between one and six, with an average of three to four. Guinea pigs are well developed at birth. They weigh between 50 and 100 grams and have a full hair coat. Babies are even born with teeth and with their eyes opened. Guinea pig young can eat solid food and drink from a bowl shortly after birth, but it is recommended to allow them to nurse for three weeks before weaning.


Slobbers/Dental Malocclusion

Slobbers is the condition where the fur under the jaw and down the neck remains wet from the constant drooling of saliva. The primary cause is overgrowth of the guinea pig’s premolars and /or molars. Most often this condition occurs in older guinea pigs and usually involves the premolars. Correction of the problem involves trimming of filing of the overgrown teeth as they develop.


Guinea pigs cannot manufacture their own Vitamin C and must receive an adequate supply from outside food sources. Lack of sufficient Vitamin C results in scurvy. Signs of scurvy include poor appetite, swollen painful joints and ribs, reluctance to move, poor bone and teeth development, and spontaneous bleeding. If untreated, scurvy can be fatal. Affected animals must be treated early with supplemental Vitamin C (given in food, water or by injection).


Hair loss is a common problem in guinea pigs. “Barbering” occurs when guinea pigs chew on the hair coats of other guinea pigs that are lower in the social “pecking order”. There is no treatment for this condition except separating guinea pigs if it becomes a serious problem. Hair loss or hair thinning also commonly occurs among sows that are repeatedly bred or weakened, as well as newly weaned juvenile guinea pigs. Fungal diseases, external parasite infestations and metabolic disorders can also cause hair loss.

Heat Stress/Stroke

Guinea pigs are very susceptible to heat stroke, particularly those that are overweight and/or heavily furred. Environmental temperatures above 85°F, high humidity (above 70%), inadequate shade and ventilation, overcrowding, and other stresses are additional predisposing problems. Signs of heat stroke include panting, slobbering, weakness, reluctance to move, convulsions and, ultimately, death. This is a treatable condition if recognized early. Heat stressed guinea pigs should be misted with cool water, bathed in cool water, or have rubbing alcohol applied to its footpads. Once this first aid measure is accomplished veterinary assistance should be sought. Prevention of heat stroke involves providing adequate shade and proper ventilation. If indoor, air conditioning during the heat of the summer provides the best relief.

Sensitivity to Antibiotics

Guinea pigs are very sensitive to certain antibiotics, therefore, never attempt treating your guinea pig at home without first consulting a veterinarian. Even some topical antibiotics can produce serious detrimental results.



Pneumonia is one of the most common bacterial diseases of the pet guinea pig. Respiratory infections are caused by a number of viral and bacterial agents. Conditions of stress and inadequate diet will often predispose a pet to an infection. Symptoms of pneumonia may include difficult breathing, eye or nose discharge, sluggishness and loss of appetite. In some cases, sudden death will occur without any of these signs.

Bacterial Enteritis

Numerous bacteria are capable of causing infections of the digestive tract. Some of these bacteria are introduced through contaminated greens or vegetables or in contaminated water. In addition to diarrhea, other common symptoms associated with intestinal disease are sluggishness and weight loss. However, sudden death may occur before these signs appear. A veterinarian will determine the best means of treatment based on the severity of infection and causative bacteria.

Bacterial Pododermatitis (Sore Hocks)

Severe infections of the footpads are very common among guinea pigs housed in cages with wire flooring. Fecal soiling of the wire worsens the problem. Symptoms of this condition include swelling of the affected feet, lameness and reluctance to move. Improved sanitation and cage floor alterations are the initial steps in correcting the problem.


Ringworm is a skin disease caused by a fungus that typically appears as patchy hair loss on the face, nose and ears. The skin in these areas may look flaky and scabby. In affected animals, the hair loss spreads along the guinea pig’s back. Ringworm may be transmitted from guinea pits to people, therefore, it is very important to limit or restrict handling of ringworm-infected guinea pigs. Thoroughly wash your hands after handling an affected pet.

External Parasites

Lice and mites are the most common external parasites of guinea pigs. These parasites are transmitted through direct contact with infested guinea pigs. Lice are tiny insects that live within the hair coats of infested animals. Mites are microscopic, spider-like organisms that infest the top layers of the skin causing an intense itching and scratching with considerable hair loss. These parasites are treated with appropriate antiparasitic drugs. In the mean time, replace wood shavings used as bedding or litter with paper toweling.


Specific Name Cavia porcellus
Life Span 4 to 5 years
Environmental Temperature Range 65° to 70°
Desired Relative Humidity Range 40 to 70%
Breeding Age Males (1st mating) 3 to 4 months (male)
Breeding Age Females (1st mating) 3 to 7 months – not after 7 months
Gestation Period 63 to 70 days
Litter Size 3 to 4 average / 1 to 6 range
Weaning Age 2 to 3 weeks

American Cavy Breeder Association at

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Click here to learn more about the Staint Francis Pet FoundationClick here to contact the Saint Franics Pet Foundation