Guinea pigs are good pets for young children and people who have never had a pet.  Guinea pigs do not intentionally bite or scratch.  If the animals are frightened, they may freeze their movements, whistle, whine, chatter (short calls) or scatter their food and water.  They are herbivores that are related to chinchillas and porcupines.  In Peru, where they originated, they are also used as a food source for people.

     The guinea pigs can have many colors and coat types.  The average pig has a life span of 4 years, although with good care living 6-7 years is not unusual.  They can start breeding at 2-3 months of age.  Pregnancy is usually 68 days (a 58-72 day range), with the female giving birth to a litter of 3-4.  As with pigs, male guinea pigs are called boars, while females are called sows.  Determining the day of parturition is not possible; the sow has her litter, without any signs to look for.  One male can have a harem of 4 to 10 females.  We advise that if you plan to breed your female pigs, breed them before 7 months of age.  After 8 months, the pelvis fuses in females that have not been bred, and if they are bred later, they may have difficulty giving birth (dystocia).  A guinea pig having her first litter after 1 year of age will almost always require a cesarean; many guinea pigs do not survive a c-section.  Obesity and improper nutrition also can cause dystocia.  The baby guinea pigs should be weaned between 3-4 weeks of age to prevent pregnancy.

     We advise housing your guinea pig in an area greater than 200 square inches, or at a minimum of 1 square foot per pig.  Housing too many pigs together may cause some dominant animals to pull the hair of other submissive pigs.  The walls can be as low as 8-10 inches high to prevent them from escaping, but we advise a 12″ cage height.  A screen top on the cage will prevent cats (and dogs) from bothering your pet.  Aquariums can make ideal houses.  Use aspen wood shavings or shredded newspaper for the litter.  We do not advise cedar, redwood, other aromatic wood shavings, or pine shaving from non-kiln-dried lumber for rodents. The temperature of the room should be the same as the house (65 to 75 degrees).

     It is important to realize that the guinea pig requires vitamin C in their diet.  Most other animals, except man, can manufacture their own vitamin C.  Any food over 3 months since its manufacture will have the vitamin C (ascorbic acid) degraded if it was added.  Over 50% of the vitamin C will be lost in 6 weeks.  A diet with a vitamin C content of less than 50mg/kg of food can cause scurvy; 200mg of vitamin C per 1 kg (2.2#) of diet is the higher level to look at when purchasing.  We have chewable tablets available at 50 mg/tablet; for the average guinea pig, this is 1/4 of a tablet a day as a treat.  The dose of vitamin C needed is 10-30 mg/kg/day.  Because of the rapid decomposition of vitamin C, it is possible in a group situation to add vitamin C to the guinea pigs’ diet at 400 mg/1#. In a group one can instead add 200 mg of Vitamin C per quart (or liter) of the guinea pigs drinking water; this corresponds to 25 mg per 1/2 cup (4 oz.) of water.  We advise purchasing Vitamin C from a drug store or other quality source.  The dry, powder forms are more stable than a liquid type from an open or dropper-type jar.  (A teaspoon of Tang contains 15 mg vitamin C, and can be substituted yet we do not recommend Tang because of the sugars in this product.  Some forms of the human chewable vitamin C contain xylitol, which is toxic to dogs and possibly guinea pigs.  Some pregnant guinea pigs may need up to 25-50 mg of vitamin C per day.  We advise the more concentrated forms of pure vitamin C if you do not buy the guinea pig labeled tablets.  Some fresh kale or cabbage can also be fed to help ensure that vitamin C is included in the diet.    

     You should feed a diet of approximately 18-20% protein, 16% fiber, and 4% fat.  These diets are commercially available for guinea pigs.  Rabbit pellets alone are not adequate in nutrition for guinea pigs.  The average guinea pig weighs up to two pounds and eats 6% of its body weight daily.  The guinea pig must be supplied with fresh water and usually drinks 10% of its weight per day.  After a guinea pig is mature, we recommend you feed mostly a diet of grass hay.  Alfalfa or alfalfa pellets contain excess calcium, which can contribute to urinary stones.  Spinach, parsley, and excess vitamin C (over 50-100 mg/day) also can create oxalate stones.  As a general rule, guinea pigs and other pocket pets should not have seeds or especially fruit as over 5% of their diet.  The longer hair guinea pigs can develop hairballs, besides brushing with a comb a high-fiber diet (hay) is recommended; all guinea pigs should be fed grass hay as a majority of their diet.  A periodic collection and testing of the urine is recommended periodically with mature guinea pigs.  Examine the habitat daily to ensure there are new stools and that water is being consumed, especially if using a water bottle. 

     We do not recommend housing guinea pigs with rabbits.  Rabbits can be a carrier of the bacteria called Bordetella.  Although Bordetella is usually a benign problem in rabbits, it causes severe pneumonia in guinea pigs.  Routinely there are no vaccinations required for guinea pigs, although we do advise a fecal exam for internal parasites occasionally.

The Staff at the Nelson Road Veterinary Clinic

303-678-VETS(8387)