General Information
Guinea pigs, also called cavies (or cavy for a single guinea pig), originated in South America. They became favorite pets in the early part of the 16th century. Guinea pigs are also bred as show animals with a wide variety of coat colors and fur types.
The three most popular breeds (there are probably 13 or more different breeds) are:
- English or common with short, straight, fine hair
- Abyssinian with rough, coarse hair growing in rosettes or whorls
- Peruvian with long, straight, silky hair.
Guinea pigs come in a wide range of fur colors and patterns as well as a hairless breed called a “skinny pig.” Males are called boars and can weigh 900-1200 grams (2-2.6 pounds); females are called sows and tend to be smaller, weighing closer to 700-900 grams (1.5-2 pounds).
"Guinea pigs come in a wide range of fur colors and patterns, as well as a hairless breed called a skinny pig."
Guinea pigs live an average of 5-6 years although some can live to 8-10 years of age. All of their teeth grow continuously throughout life and it is critical that they eat mostly grass hay (such as Timothy hay) every day to help them wear down their teeth. Guinea pigs, like humans and primates, require a dietary source of vitamin C because their bodies cannot produce vitamin C on their own.
Guinea pigs have scent glands over their backs at the base of their tails, that in older animals can become impacted with secretions, making their skin appear greasy there. This is especially true in male guinea pigs. Guinea pigs have 4 toes on the front feet and 3 toes on the back feet.
If a guinea pig senses danger, it will either freeze or make an explosive attempt to run away. Guinea pigs do not see well but have well developed senses of smell and hearing. They are communicative and use a wide variety of sounds to express themselves. Guinea pigs display a unique behavior called popcorning which involves jumping from excitement.
"Young guinea pigs display a unique behavior called popcorning when they are happy, in which they jump straight up in the air and let out squeals of delight."
Guinea pigs can be hardy and easy to care for when provided an appropriate environment for their unique needs. When handled frequently and gently, guinea pigs can make great family pets, especially for families with children. They rarely bite or scratch and are docile, non-aggressive, highly interactive and affectionate animals.
Housing
There are a large variety of hutches and cages commercially available for guinea pigs. Guinea pigs should be kept indoors but need supervised time out of their cages each day to run around and exercise. An indoor cage size minimum of 24" x 36" (60 cm x 90) should comfortably accommodate a guinea pig. Remember, bigger is better.
Guinea pigs should have access to supervised outdoor time so that they can receive UVB light and consume non-pesticide treated grasses and dandelions. The outdoor temperature should not exceed 78°F, and guinea pigs should be provided both water and access to shade. Ensure that a hidey hut is also available. Depending on where you live, you may need to watch for birds of prey to protect your guinea pig
Guinea pigs are highly social animals and do better with a cage mate. Therefore, it is recommended that at least 2 guinea pigs be kept together, which means the cage may need to be larger. In some countries, it is actually illegal to only have one guinea pig in a household. However, if the sexes are mixed, they will readily mate and quickly increase in number. To avoid this problem, guinea pigs should be kept in same sex groups or the male should be neutered at a young age.
Spaying the female is an option, but a more involved and difficult procedure.
Even though guinea pigs are not good at jumping or climbing, the cage should be secure and at least 10" (25 cm) in height. Cages can be constructed of plastic, metal, or wire as long as they are easy to clean daily. Solid flooring is best, as wire mesh floors can cause injury to guinea pigs’ feet, causing sores (a condition called bumblefoot or ulcerative pododermatitis).
Shredded newspaper or commercially available recycled paper products make the best bedding, as they are safe if ingested and are not dusty or irritating to the respiratory tract. Wood shavings should not be used in Guinea Pig cages as they can be irritating to the respiratory tract. Some types of wood shavings can even cause liver damage.
Guinea pigs can quickly make a mess of a cage so cages need to be spot-checked daily and thoroughly cleaned at least once weekly. More guinea pigs will mean larger, more frequent messes. Cleaners such as diluted white vinegar and/or Dawn dish soap can be used.
"Solid flooring is best, as wire mesh floors can cause injury to your guinea pigs’ feet, causing sores.”
Food dishes should be large heavy ceramic crocks that are hard to tip over. Water can be provided through both a water bowl and a sipper bottle; both should be cleaned and replaced with fresh water daily. Generally, guinea pigs will prefer sipper bottles. A small upside-down box or container with a cut out for a door is a welcomed hiding area. There should be at least one hidey-hut for every guinea pig in the cage to reduce competition for resources. Foraging items, chew toys (such as apple sticks), and other toys for enrichment should be provided at all times. Temperatures between 65-80°F (18-26°C) are ideal. Anything over 80°F (27°C) will increase the likelihood of heat stroke, especially in animals that are overweight or pregnant.
Nutrition and Feeding
Guinea pigs are completely herbivorous and have a large hindgut-fermenting system that consists of a very large colon and cecum. The bacteria that are present are in a delicate balance to produce some of the nutrients that are passed through in feces and then re-ingested by guinea pigs. Therefore, it is normal to see your guinea pigs bend down and directly consume feces. This is known as coprophagy and is a very important part of guinea pig health and nutrition. Guinea pigs should be evaluated by a veterinarian if they do not perform this behavior, because loss of coprophagy can lead to weight loss and malnutrition.
Guinea pigs should consume 75% of their diet each day in the form of good-quality grass hays, such as timothy hay and orchard grass. Alfalfa grass should only be offered to pregnant or nursing female adults, and young guinea pigs until they are 6 months old. A variety of leafy greens and vitamin-C-rich vegetables can comprise 20% of remaining diet, and the final 5% should be high-quality timothy-hay based pellets. Leafy greens should be lower in calcium or oxalates to prevent urinary stones. Vegetables that are high in vitamin C include red and green bell peppers, parsley, cauliflower, and broccoli. Fruits and treats should be offered sparingly, if at all. Yogurt treats should not be provided as the high sugar content can cause an upset stomach or lead to obesity if given frequently.
Vitamin C should not be added to the water because it can change the taste of the water, which may lead to decreased water consumption. Furthermore, vitamin C degrades rapidly in water so is not a long-term feasible supplementation for guinea pigs. Commercial vitamin C tablets designed for small mammals are available at major pet stores nationwide, and should be provided in addition to the vegetables mentioned above. A liquid vitamin C supplement can also be provided by mouth if your guinea pig will not eat the tablets.
"Vitamin C should not be added to the water because it can change the taste of the water..."
Commercially available pellets made for guinea pigs contain vitamin C; however, this vitamin is relatively unstable and breaks down very rapidly. Therefore, the pellets should be used or completely replaced within 90 days of the date of manufacture.
Breeding
Guinea pigs reach sexual maturity at around 3-4 months of age. However, males can begin to mount females at 3-4 weeks of age and females can become pregnant as early as 2 months (7-8 weeks old). Males and females should be separated from their mother no sooner than 2-3 weeks to prevent developmental problems, but should be separated right after this time to prevent unwanted breeding.
After about 8 months of age, the female guinea pig's pelvic bones become more tightly fused, and if she has not had a litter by that time, giving birth can be more difficult. Sows give birth to 2-4 fully developed, relatively large, fully furred pups with open eyes and the ability to eat solid food (although they will still nurse). A baby guinea pig is called a pup or young, but not a piglet.
The average gestation period for guinea pigs is 63 days. If gestation continues over 70 days, the guinea pig should be seen immediately by a veterinarian, with high risk that the entire litter could be stillborn. As with many rodents, the female guinea pig will be able to mate within a few hours of giving birth but should not be allowed to; she needs time to recover and replenish her metabolic reserves before becoming pregnant again. If your guinea pig has a large litter (over three or four pups), consider fostering one or more of the pups to another female, since guinea pigs have only two nipples for nursing their offspring. This is something to discuss with your veterinarian.
