why did she have a miscarriage

Question
hi, let me first start off describing the situation
i have 7 guinea pigs 3 boys 4 girls

the two oldest have had a litter on nov.5 2006

2 babies came. one boy one girl

wee seperated them son with father

daugher with mother


then one day we put mom and dad together and i guess she got pregnant

but we put her back in the cage with her daughter

just like 30 minutes ago me and my bf noticed blood on her mouth and on the cage floor

we looked inside and there was one whole baby (dead) and  another bloody thing that we couldnt make out (we thought it was a torn up body)

but what we cant figure out is why she would have a miscarriage


is this normal

the baby seemed to be so close to being born


can u help me out?

Answer
The other boody thing in the cage was the placenta of the baby. She was most likely due at that time if the baby was fully developed. Also if the mom was in with the father of the first litter of babies when they were born, she most likely got pregnant again, as females go into heat right after birth. I would not breed her again though, it could have possibly been that she didn't have a long enough break in between litters, but almost always mother pigs do not clean their babies off for a reason, in most cases one of the parents has a background with some inbreeding in it. If you do try to breed her ever again though, be sure to wait at least 3-4 months in her case before placing her with a male.
Brittany