How long are guinea pigs fertile?

Question

I have a 2-year-old male guinea pig but am thinking of adopting an abandoned guinea pig. The problem is that the foster home doesn't know what s*x the guinea pig is. If it's male, I don't have any problems (they can have separate cages), but if it's female, I don't want a litter of guinea piglets!

So, do guinea pigs stay fertile all of their lives? Or do older guinea pigs reach a sort-of "menopause" so I can safely let an old male and female piggy play together?

Answer 1

If it's a male and they can have separate cages, why if it is female can't it have separate cages as well? Seeing as you do not want a litter of guinea piglets... LOGIC my dear. LOGIC.

Answer 2

what do you mean by fertile?

Answer 3

As to estrus - The time prior to estrus, called proestrus, lasts about 1½ days. During this time, the sow shows increased activity and mounting behavior. The fertile period, called estrus, lasts 1-18 hours with spontaneous ovulation occurring about 10 hours after onset of estrus. As far as what age do they go into a guinea pig type of menopause?  I don't think they do.  From what I can tell, they stay fertile to the end.  As you already know, the only way to ensure your older piggy does not have an unwanted pregnancy is to neuter or spay or to maintain celibacy.