Hello, I'm Dr. Zoe. BAsed on what you have described I am very concerned that your guinea pig may be in a crisis that we call dystocia or difficulty giving birth. This is a veterinary emergency as these guys can die from being unable to whelp. She is at the upper threshold for age to breed. I'm sure your aware in guinea pigs the ideal age to breed is between 4 and 7 months. Older than this and the pelvic symphysis (this fuses together to two sides of the pelvis) may be fused and therefore when she gives birth it cannot open as it should to allow the babies to pass. This is certainly possible to be going on with her.

That is excellent! It means she CAN pass the babies. However, my rule for whether this is an emergency or not is any gravid guinea pig that is straining for more than several minutes, depressed, or where the pelvic symphysis has not separated should have a caesarean section considered. Traditionally, guinea pigs undergoing a caesarean have been given a poor to guarded prognosis. I have found this not to be the case, with the majority of guinea pigs I have operated on surviving the surgery, with the pups viable. The key, in my opinion, is to detect early signs of difficulty, and electing to perform the caesarean early rather than waiting or fiddling around trying to establish a stable patient.

I recommend keep her in a quiet, dim environment. Try not to disturb her too much (that means don't pick her up or touch the other babies). If she doesn't produce another baby within 1 hour and continues to strain you should take her to an emergency clinic tonight. She may not make it until the morning. Do not try to feed her.

It should not make a difference at this point. Poor little guy. I'm sorry that you lost the first two. Best of luck.

Let me know if you have further questions