There are so many unwanted guinea pigs available to adopt from shelters and rescues no one needs to breed pet guinea pigs.
Some guinea pig owners, however, will still want to breed their piggies for show or certain traits such as temperament.
If you want to breed your piggies, there are some things you need to be aware of concerning age before breeding.
Guinea pigs should not be bred after 4 years, and even after 2 years, they’re at high risk for medical issues. The optimal breeding age for male and female guinea pigs is between 6 and 24 months. Females must first be bred before 7 months of age, or they won’t be able to give birth naturally.
Male guinea pigs, or boars, are sexually mature from 2-3 months, but their sperm may not mature until about 4 months.
Sows are sexually mature at 2 months of age but should wait until they are fully mature to breed.
Read on for more about breeding guinea pigs.
How Old Is Too Old To Breed A Guinea Pig?
The best age to breed your pigs is from 6-24 months, after which health risks increase as your guinea pigs age.
Breeding after 2 years can incur reproductive complications, such as dystocia, which is the inability of the sow to deliver her pups.
Litter size will decrease, and health problems can ensue from pregnancy in guinea pigs at too advanced an age.
The first litter should be before the female’s pubic symphysis calcifies, or she will not be able to deliver the pups.
When there are fewer pups, they are often born large, which can complicate the gestation and birthing process.
Other complications with pregnant and post-partum sows are low calcium, eclampsia, mastitis (an infection in the mammary glands), and uterine prolapse.
Can Guinea Pigs Have Babies at 2 Years Old?
While guinea pigs can have babies at 2 years of age, it is not recommended.
If the sow has not been bred before, it is not a good idea; it is very likely the sow and pups will die.
The ideal breeding age is from 6 months to 2 years, so if you have a healthy, proven breeding pair, one more litter probably won’t hurt.
As guinea pigs age, pregnancy brings considerable risk to the mother.
Male Vs. Female Maturity
Boars are sexually mature from 2-3 months of age but should not be bred until at least 4 months, so their sperm is viable and healthy.
It is better not to pair an older boar with a too-young female because they might want to mate before the female reaches sexual maturity, which is 3-4 months.
How to Introduce and Breed Guinea Pigs
Males should be introduced to the females slowly, first by smelling each other in close proximity, followed by in person.
Make sure you have a separate area for the two piggies in case the introduction takes a while.
It is less stressful for the female for the male to enter her domain rather than the other way around, although introducing on neutral ground is ideal.
Monitor their interactions closely for any signs of incompatibility or aggression, which is rare but can happen.
Sows are fertile, or in heat, about every 16 days, so if you leave this pair together for the next 20 to 48 days, the sow will have 3 opportunities to become pregnant.
After the 48 days, remove the boar so the female can focus on her pregnancy and prepare for her litter.
Sows birth better alone.
Separation is also a good idea because the boar will be ready to mate again after the sow delivers.
This is not a good idea as the sow will come back into heat in as little as 15 hours, and you’ll have more baby guinea pigs whether you planned for them or not!
If you have more females in a colony, the pregnant sow can usually live with them amicably.
The other sows will act as mothers to the pups.
How Can I Tell If My Guinea Pig Is Pregnant?
An obvious sign your piggy is pregnant is when they begin to eat a lot more and gain a visible amount of weight.
A pregnant guinea pig begins to look as wide as she is long!
If you suspect your piggy is pregnant, confer with your vet.
Further Reading: Guinea pig weight gain during pregnancy.
How Long Do Guinea Pigs Gestate?
Guinea pig pregnancy lasts between 60 and 72 days.
A longer gestation period can mean health issues and lead to a miscarriage so keep a close watch.
Do not handle your piggy more than necessary to reduce stress and lessen the chance of injuring a baby.
Ensure your pregnant guinea pig has plenty of fresh water and food with lots of calcium.
Sows typically have 2-3 pups in a litter but can have up to 8.
The record number of pups from one litter is 17, which is mind-boggling.
The more pups there are, the smaller they are.
Your piggies can have up to 5 litters a year.
Newborn guinea pigs, or pups, are born precocial, which means they have teeth and fur and can squeak and run around like adults when they are born.
The babies nurse within the first few days to get colostrum and eat solid food such as hay pretty soon after birth.
Young are fully weaned between 2 and 4 weeks of age and need the male, and female guinea pig pups need to be separated as soon as possible to avoid any unwanted pregnancies.