The pregnant guinea pig often gains a lot of weight and looks pretty plump. Guinea pigs usually give birth to their young after a gestation period that lasts between 63 and 70 days. The length of the gestation period is reduced by one day for every additional baby that the mother is carrying. It is normal for pregnant guinea pigs to have a trouble-free pregnancy; nevertheless, it is important to remember that each time an animal is pregnant, and especially in the later stages of the cycle, the animal’s behaviour and personality can alter.
Keep a close eye on things as they unfold. This latter stage of pregnancy is when pregnant guinea pigs are more prone to heat related death. Mums have been known to abort the fetus if something dramatic happens.
When you have a pregnant guinea pig, try not to over handle her. If you have to pick her up, make sure that you fully support her hind quarters.
During the first 4 weeks of pregnancy you will notice very little change in appearance or behavior, but in the last 2 to 3 weeks the new mum will become very plump, even chubby. As her babies will make up more than half her total body weight, this new shape is to be expected. In the last 2 weeks it is normal to not only feel the babies moving but you should also be able to see them moving. During pregnancy and as long as you are sure that she is pregnant, you might want to increase the amount of protein and calcium in mum’s diet. Don’t overdo it, and maybe consult your vet prior to making this adjustment. Hair thinning is a common occurrence in the latter period also, so an increase in fiber may assist with that.
Pregnant guinea pigs very rarely need any help giving birth, unless they are older and it is their very first pregnancy. As the first time mother gets older (before giving birth), her hip bones grow closer together, which can cause birth problems. Pregnant guinea pigs, over the age of 6 months, are at great risk. Make a trip to the vet when you know she is pregnant, he will be able to give you an idea of the expected birth date, and also schedule a caesarian, which could ultimately save her life. Remember that at 3 weeks prior to the expected birth, the babies can be seen moving, so as soon as you see this happening, you know the birth is only weeks away.
Under normal circumstances, pregnant guinea pigs will give birth during the hours of daylight. The process itself will usually last no more than 20 minutes, and the first baby should be showing up within 5 minutes of the mother going into labour. Normally there will be a 3-5 minute gap between babies, and she will usually give birth to around 3 babies. On rare occasions a guinea pig will have up to 8 babies, and sometimes only one, but generally the average is 3. If her labour lasts any longer than this, get ready to take her to the vet in a hurry, as she could die of exhaustion. The mum will remain sitting as the babies pop into the world from underneath, head first.
As each baby emerges the mum will clean each one, and she will reach between her legs with her teeth to remove the amniotic sac. When they have all been born, she will release a little blood and the placenta, which she will eat later. Once she has the babies in her care she will start to build a soft nesting place for newborns. You would want to make sure she is separated from other guinea pigs by now, and give her the materials and space to care for her babies.