Guinea Pigs – some facts

The guinea pig or cavy is a docile rodent native to the Andes Mountain area of South America. They were first domesticated by the Andean Indians of Peru who used them as a food source and as a sacrificial offering to Incan gods. During the 16th century, Dutch explorers introduced guinea pigs to Europe where they were selectively bred by fanciers. The guinea pig entered the research laboratory in the 18th century and have since made significant contributions to the scientific community. To this day, the guinea pig remains a favorite pet among children due to their docile behavior, ease of handling, and clean, quiet nature.

Diet

Good quality food and fresh, clean water must be readily available at all times. Do not feed commercially available “rabbit and guinea pig” mixes These mixes are far removed from natural food for guinea pigs and contribute directly to the poor health seen in many middle-aged and older guinea pigs.

Unlike most mammals, guinea pigs cannot manufacture their own vitamin C, therefore they must receive it from an outside source. We recommend feeding foods high in Vitamin C, such as oranges, capsicum and tomato. In addition, fresh greens, pasture / grass hay, and small amounts of fruit may be offered daily with some precautions. These foods must be thoroughly washed to avoid exposing your pet to pesticide residues or bacterial contamination. Any change in the guinea pig’s diet should be made gradually due to their sensitive digestive systems.

Where possible, your guinea pig should have access to grass every day. Not only is grass a more normal diet for them, but chewing it helps to keep the teeth from overgrowing and developing sharp points that can cut the tongue and/or cheeks.

Guinea pigs tend to be creatures of habit, and therefore, do not tolerate changes in the presentation of their food or water nor changes in the taste, odor, texture, or form of the food itself. Pet owners should avoid making radical changes in the food or water containers as well. Any sudden change in routine can result in the pet refusing its food and water which can be disconcerting and ultimately dangerous.

All foods should be provided in heavy ceramic crocks that resist both tipping and chewing. 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 by chewing on the end of the sipper tube and ‘backwashing’ food particles into it. For this reason, it is imperative that all food and water containers be cleaned and disinfected daily.

Housing

There is no single correct way to house your guinea pig as long as the well-being of your pet is considered. Adequate housing is a major factor in the maintenance of healthy pets. The basic requirements for housing are:

• room to move around and exercise – allow 1m sq. per adult guinea pig
• safety from attack by dogs, cats and other predators
• easy to clean – guinea pigs are VERY messy
• guinea pig-proof – both from escape and from consumption. The height should be at least 40cms, and the hutch constructed of wood or steel
•  avoid wire floors as these damage the guinea pig’s feet, leading to severe infections (pododermatitis)
• a ‘privacy area’ must be provided for guinea pigs to hide
• temperature extremes must be avoided – especially heat
• Bedding materials must be clean, non toxic, absorbent, relatively dust-free, and easy to replace.

Handling

The Guinea pig’s natural curiosity and friendly disposition makes it fairly easy to handle. Most Guinea pigs will approach a hand introduced into their cage and can be easily scooped into the palm of the hand. Usually, cupping one hand under the rump while the other hand cradles the midsection is a good way to pick up guinea pigs safely. Two hands are recommended so that nothing is left dangling and because there is less risk of dropping them. Guinea pigs are quite nose-heavy, and will do a potentially injurious nosedive if dropped. Guinea pigs not accustomed to being handled may jump and run, but rarely turn aggressive.

Reproduction

An 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. If the first breeding is delayed much beyond this time, serious and often fatal problems with delivery may result. The reason for this is that the pelvis of the guinea pig fuses at this early age which narrows the birth canal and prevent the babies from passing easily. Males (boars) should be at least four months of age before breeding.

The sow’s oestrus cycle (‘heat’) lasts 14 to 19 days. The actual period in which the sow is receptive to the boar for breeding is approximately eight to fifteen hours during this cycle. Sows often return to ‘heat’ within a few hours after giving birth. This time is known as ‘postpartum estrous’ which means that she can be nursing one litter while being pregnant with another.

Pregnancy lasts between 63 and 70 days. The gestation is shorter with larger litters and longer with small litters. This duration of pregnancy is relatively long when compared to other rodents.

Pregnant sows exhibit a grossly enlarged abdomen during the later stages of pregnancy. Her body weight may actually double during pregnancy. The time of delivery is difficult to assess in guinea pigs due to the relatively long gestation period and lack of nest building by the sow. Within one week prior to delivery, a slight widening of the pelvic area can be noted. If this separation of the pelvis does not occur, then it can cause the delivery problems mentioned previously. Therefore, sows bred past seven months of age may require caesarean section for delivery of the young.

An uncomplicated delivery usually takes about one-half hour with an average of five minutes between babies. Litter sizes range between one and six with an average of three to four. First time litters are usually very small. Unfortunately, abortions and stillbirths are not uncommon with guinea pigs.

The young are very well developed at birth. They weigh between 50 and 100 grams and have a full hair coat. Babies are even born with teeth and open eyes. Mothers are not very maternal in the raising of the offspring in that she does not build a nest and even remains in a sitting position while nursing. The young can actually 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.