guinea pig breeding.

Question
What are the odds of a guinea pig getting pregnant within one week.  The sow is about 2 years old and the male is 2 months.  I know this is not a good thing so I am very concerned.

Answer
Hi Karla,

Unfortunately the odds are high.  You will need to separate the animals immediately.

If your female has never been bred before count on her needing a Cesarean section to deliver - the bones on female guinea pig fuse at about 8 months to one year old.  

Watch her closely - gestation is between 68 to 72 days generally (it can be longer or shorter of course).  She will get obviously fatter starting around 5 or 6 weeks after conception.  At two years old she may produce a very small litter of only one pup (2 to 3 is average, although they can have from 1 to 8 - my largest litter ever was 6)  The smaller the litter size, the larger the pup(s) will be so that adds to the problem.  Don't take her anywhere during the middle of her pregnancy as this is the most dangerous time to stress a sow.  You may take her to the vet when she appears to be close to term.  Please make sure the vet knows about guinea pigs, they do not handle anesthesia well and need a vet with experience.

There is of course a slight chance she didn't get pregnant, but you really can't count on it.

Annie