If you’ve got two opposite-sex guinea pigs, you can expect them to multiply!

But hold on there.

Guinea pig breeding is risky, at best.

The females are prone to pregnancy complications, and it’s difficult to place the babies in good homes.

Females become capable of reproducing by the age of four weeks.  The males reach sexual maturity at the age of three weeks!

When the female is in her reproductive cycle, there is no bloody discharge to warn you.  If she is impregnated, the gestation period runs from 59 to 73 days.

Expect one to four babies to be produced in each litter, but the head count can go as high as seven.

A sow that carries a large litter often grows too miserably huge to move by end of her term.

There are many people who think it’s easy to breed guinea pigs.  Maybe they’ve had one uneventful experience and so they figure another one will be easy as well.  Or they know someone who has a guinea pig breeding story to tell.  But if they try it again they will likely end up with a sad tale about the mother dying before she has even finished birthing her pups.  The odds are against repeating successful breeding.

One of the most difficult complications of guinea pig breeding is that babies are large and fully active at the time of birth.

High Risk

As many as 20% of all sows, as the pregnant females are called, die at childbirth.

These deaths result from circulatory failure caused by the weight of the pups she is carrying, prolapsed uterus, dystocia (stress from slow labor), calcium deficiency (the pups take the sow’s calcium, much like a human baby does), or toxemia (which carries a plethora of deadly symptoms).

The sow cannot begin a first pregnancy after the age of 8 months.  The risk of death from dystocia increases by that age.  Often they suffer complications because the pubic bones have been fused by cartilage.

Once your sow gives birth, it is only two to fifteen hours until she is able to conceive again.  That means if Daddy is still in the area, put him-and all his good buddies-into a separate cage before the birthing begins.

You should also consider your level of preparedness before you take on breeding.  Do you have the money for veterinary bills?  Can you provide cage space for all the animals?  Will they go to proper homes?  It takes up to 21 days before the pups can be weaned.

The males and females should be separated by three weeks of age.  The female pups can remain with their mother, and the males will enjoy living with an older male guinea pig.  Guinea pigs do not withstand neutering very well, so the best type of birth control is to keep the sexes separated.

All of this advice leads you to one inescapable conclusion:

For your pet’s sake, you should avoid guinea pig breeding.  If your pet does become pregnant through accidental mix-up of sexes or a similar circumstance, watch your sow’s health carefully.  Weigh the pups daily after they are born to ensure that they all thrive. Have an exotics vet on standby.

There are some tips to help you plan for the stages of guinea pig pregnancy here.

Most people like to keep guinea pigs all of one sex to prevent pregnancies; keep that in mind as you find homes for the pups.