Guinea Pigs' age of first birth

[dominicgarcia]

I am NOT looking for info because I want to breed, I just am curious. At what age is too old for a female to have her first litter? From everything I’ve read it says not to breed them for the first time if they are over 8 months old. Someone is telling me the info on this site is outdated but I don’t believe that. Can anyone tell me if I’m right? Thanks!

[Lynx]

I believe you are correct.

If you have read this page:
https://www.guinealynx.info/reproduction.html

...it states:

Breeding after 8 months of age can be fatal for a guinea pig that has not had a previous litter due to dystocia. The symphysis (a joint of tough fibrous cartilage which firmly joins the 2 pubic bones) becomes less flexible upon reaching adulthood and may not separate fully, making delivery difficult.

Harkness and Wagner in The Biology and Medicine of Rabbits and Rodents describe how the pubic symphsis begins to separate late in the pregnancy due to the hormone relaxin. About 48 hours before birth, you may be able to feel a gap of 15mm or so. At birth it can increase to 2.5 cm (1-1.5"). "If the first breeding is delayed past 7 or 8 months, the symphysis separates less easily, and fat pads occlude the pelvic canal. Such impediments may lead to dystocia and death, especially when small litters of large young are involved)."
Sows with dystocia usually need a caesarian section. The survival rate is very poor. Spaying or neutering guinea pigs also carries risks even when performed by an experienced guinea pig veterinarian. The safest choice is to keep the sexes separate or have only sows or boars. Sows who become pregnant at an older age can sometimes deliver successfully but because of the added risks, pregnancies should be avoided. All pregnancies carry risk.

If your older sow has become pregnant, the safest course is to allow the pregnancy to procede normally but line up an experienced vet in case there are complications. Another alternative is terminate the pregnancy. All surgery also carries risk.Go Up

A number of factors can contribute to the risk of pregnancy in older guinea pigs. That is not to say a pregnancy cannot be carried to term, just that there is an increased risk of complications.

People can make their own decisions. However, some of those decisions can put a pet at high risk of complications. Always better not to breed when there are so many guinea pigs needing homes.

[Renonvsparky]

Buttercup was 2 and a half when she had her last litter. She had been housed with her brother, so there's no telling how many litters she had before I got her and put a stop to it. My guess is that she was younger than 8 months when she had her first one. She didn't quite make it to age 4. So, not only is it high risk to breed guinea pigs, it is possible that it will shorten their life.

[SardonicSmile]

I had one girl who was pregnant when I got her and she was not even two months old at the time. She lived to be over five years old. While it didn’t seem to affect her much, her backside was never really right. My cousin didn’t like picking her up because you could just feel something was off, she felt almost bendable in ways she shouldn’t be. (I think nutritional deficits while growing herself and growing baby’s at the same time and me not knowing till late into the pregnancy.)

I adore baby piggies, but will never breed with my piggies.

[Renonvsparky]

One or two litters most likely doesn't shorten their life. Repeated litters because the owner doesn't know better than to house males and females in the same cage for the first 2 and a half years of their life probably does.