Baby Guinea Pig – Care and Development

baby guinea pig

Like babies of all species, a baby guinea pig is as cute as can be.

Maybe even more so, because baby guineas are so tiny and winsome!

This article is stuffed full of baby guinea pig facts, from what a baby guinea pig looks like, to baby guinea pig diet and development.

We’re going to look at everything you need to know if you’re thinking about bringing one or more baby guinea pigs home.

Let’s dive in!

Baby guineas

Domestic guinea pigs have been kept as pets for thousands of years.

I bet you didn’t know that cute baby guinea pigs are neither pigs, nor from Guinea—say what?

It’s true, and there are tons of other fascinating and surprising guinea pig babies facts to discover!

Domestic cavies originated in South America but today these vocal, social creatures thrive in households across the globe.

Guinea pigs are not only kept as family pets, but like dogs, cats, rabbits, etc., they are bred for show.

The American Cavy Breeders Association is just one of the international bodies that oversee breed standards and competitions.

What are baby guinea pigs called?

Guinea pigs are actually rodents, and known as “pocket pets” due to their pocket-sized stature. Gerbils and hamsters (also rodents) are other popular pocket pets.

The guinea male is referred to as a boar, the female is known as a sow, and their furry little bundles of joy are called pups.

Baby guinea pigs can expect to enjoy a typical lifespan of 5 to 8 years.

This is a longer lifespan than other pocket pets, and cavies are also larger than their pocket pet brethren.

Adult guinea pigs will grow to 1.5 and 2.5 pounds and typically grow to 8 to 10 inches long.

How many babies can a guinea pig have?

Lots of small animals – think rats and rabbits – have reputations for being prolific breeders.

And guinea pigs are quite fertile little creatures too!

With a gestation period that lasts roughly 60 to 70 days, guineas are capable of having five litters a year.

A guinea pig can have upwards of six pups, and of course as few as one.

Three pups is the average litter size although it’s been reported that the largest litter size was a whopping 17 pups!

So, if a guinea pig is capable of having five pregnancies a year, with an average of three pups each time, you can expect to be blessed about 15 times annually—if you are so inclined of course!

Although guinea pigs are able to conceive year-round, springtime is a peak window of time for baby guineas to appear on the scene.

What does a baby guinea pig look like?

A newborn pup is tailless and cylindrical and weighs between 60-120 grams.

Their eyes will open on their same day they’re born, and their ears – which look huge at the moment – can already hear.

Newborn guinea pigs already have a full coat of fur, and their tiny mouths already manage to contain 20 teeth, which grow continuously.

And what about those tiny toes?

Did you know that guinea pigs have four toes on each front paw and three toes on each hind paw?

Baby guinea pigs week by week

Baby cavies grow up all too fast just like our precious humans babies!

In fact, they are born “precocious” which means that they come into the world just about fully developed, which is totally unlike baby humans.

The development that does occur after birth is incredibly quick and we’re going to take a peek at a few of the developments that occur in the first few weeks so that there are no surprises in store!

Baby guinea pig: Week one

First off, the size of the pups at birth corresponds to the size of the litter, with more pups resulting in smaller babies.

An average sized pup measures around 3 to 5 inches at birth, roughly the size of a tangerine.

Newborn guinea pigs are described as “precocious,” meaning they are born fully developed.

They have fur as well as teeth, and they are capable of digesting solid food very soon after birth (within hours).

Within twenty-four hours they can start to eat produce, hay, and pellet feed just like the adults.

Newborns emerge with open ears as well as open eyes while the paws and head are outsized in proportion to the body.

Once it is licked by its mom, the pup will begin to wriggle and eventually move about.

Week one: What do baby guinea pigs eat?

Although they are capable of eating almost immediately, the need to nurse remains and they will seek milk about every two hours.

A pup will nurse anywhere from approximately three to six weeks.

In the first week pups can nibble on grass just a few short hours after birth, and they can be given greens regularly a day or two later.

If the babies are on the small side, your vet might suggest offering them mushy food pellets or a bit of wheat bread soaked in goat’s milk.

Always consult your vet if you think a baby guinea pig overly small, or failing to thrive.

Week one: When can I handle my baby guineas?

It is fine to carefully handle your new guinea pig pups during this time, but be sure to allow them plenty of time with their mother, as well.

I know they’re adorable, and you’ve been waiting and waiting for the pups to arrive, but it’s important to wait for at least a few hours before picking them up.

When you do approach the a baby guinea pig, be careful to move slowly and gently or you can scare the new little being.

Place one hand under the tummy and one behind the front legs and hold the little guy close to you.

Baby guinea pig: Week two

After a few days the pups can eat the whole range of adult food, which we’ll describe later on in the article.

Guinea pigs are notorious communicators and mealtime is no exception.

Don’t be surprised if your pup lets out a little chirp as a means of asking for food!

In addition cavies squeak and grunt depending on their mood.

You can also expect your pup to wander curiously about their world during this time, but their legs are still a bit clumsy and they’re apt to suddenly plop down as they explore their environs.

By this time it’s important to handle you cavy on a regular basis in order to socialize her.

Again, always take care to move toward her gently, and not thrust your hands at the pup; guinea pigs rarely bite, but if they are startled or afraid they may nip.

Socializing baby guinea pigs

Getting guinea pigs used to handling from an early age is vital part of rearing confident, relaxed pets.

But it’s even more important to make sure a baby guinea pigs stays with their mum and their littermates.

Studies have shown that animals who are raised in isolation are more likely to suffer from mental, biological, and emotional disorders.

In particular research scientists have found that guinea pigs raised without a sufficient level of interaction experience adverse brain functionality.

Baby guinea pig: Week three

This is the earliest time period in which pups may stop nursing, although many experts recommend that pups be weaned as late as 6 weeks.

Weaning age depends on several factors including the pup’s weight, the mother’s milk supply, and the number of siblings.

Mom will begin to discourage her babies from nursing at about the 3rd week.

When this occurs add in extra hay until the nursing stage is completely over. After that, hay pellets will do as they travel toward their adult size and weight.

During the second and third weeks the mom will lick a pup’s nether region as a way of stimulating the urination instinct.

This is also the stage at which the babies increasingly become independent from mom.

Baby guinea pig: Week four

Starting at three weeks and no later than four it’s time to separate the boys from the girls as females pups are now sexually mature.

It’s important to separate the litter before the siblings can reproduce as inbreeding is not a good idea for the health and well-being of future generations.

How can you tell which pups are girls and which ones are boys?

We’re glad you asked!

It’s pretty easy to do a quick identification test simply by holding your guinea baby with its tummy facing you.

Next, push oh-so-gently on the lower abdomen and watch what happens.

If a little lump extrudes from the genital region it’s a boy, if nothing appears it’s a girl.

Baby guinea pig: Week five

By week five the pups are lively and you can expect your cavies to be between 13 to 18 centimeters in length.

You will get a kick out of their eagerness to chase each other around and play, and maybe even get in a bit of “popcorning.”

What’s that, you say?

Popcorning is an incredibly descriptive term to describe the frenzied bursts of energetic jumping, bumping and hopping about that guinea pigs engage in.

Towards the end of week five, baby guinea pigs are ready to leave mum, and join their new forever home.

You might also notice young cavies start to pipe down, and their energy peaks level off.

You will observe less activity from the little guys, and when you peek in at them you will see them laying and sitting more than running and jumping.

Baby guinea pig development: Month two onwards

Since guinea pig development is just about completed in the womb they are pretty much born ready to rock and roll.

Still, there are some things that must wait, such as male sterilization, which can be done starting at three months.

If you want or need to bathe you cavy, experts suggest waiting for two months.

Like many rodents, guinea pigs sometimes participate in social grooming, and they will regularly self-groom.

Believe it or not, at around two months of age your pup may have doubled in size!

It’s not uncommon for baby guineas to be 6 to 9 inches long at week 8.

After the third month the pups will continue to grow, but at a very slow rate.

By the fourth month they should be around 8 to 10 inches in length.

And finally, at about the 9 month to 1 year mark, the cavies will have reached their final size which can be up to a foot long.

What do baby guinea pigs eat?

There are a couple of remarkable things to know when it comes to guineas pigs and their eating habits.

First off, guinea pig teeth grow continuously.

Just like Jack’s beanstalk, their pearly whites will keep on growing and growing, with no end in sight.

To combat this unique dental propensity, cavies need to chew and gnaw almost 24/7 in order to keep their teeth ground down and in check.

To achieve this, baby guinea pigs will nibble hay and fresh produce from the very first days of life.

Secondly, guinea pigs (like other rodents) do not naturally manufacture vitamin C within their little bodies, so they must have a daily of dose of the sunshine vitamin either in the form of food or a water additive.

For the first few weeks of a baby cavy’s life, good sources of vitamin C include dandelion greens, small bits of orange, and bites of kale and/or berries.

Many fruits and veg will provide good doses of vitamin C, but a supplement may be used as well.

Pregnant guinea pig nutrition

While we’re on the topic of guinea pig nutrition, it’s important to note that the diet of a pregnant guinea pig plays a role in baby guinea pig health.

One study found that restricting a pregnant guinea pig’s food intake was correlated to prenatal fat levels in her pups, which in turn could adversely affect adult metabolism and heart function.

Another study found maternal guinea pig malnutrition to be correlated to a smaller placenta, which in turn is correlated to a lower fetal weight.

So, if you plan on having your female baby guinea pigs grow up to be guinea pig moms, remember that when the time comes, their nutritional needs are more important than ever!

How to take care of baby guinea pigs

baby guinea pig

If you’re thinking of breeding from your guinea pigs, then it’s crucial to involve your vet from the very beginning.

That means even before conception, with a full health check for both parents-to-be.

Your vet will also be on hand to monitor your sow through her pregnancy, and check her litter after birth.

All being well, newborn guinea pig babies will get all the care they need from their mum until it’s time to move out.

Your main role will be handling them gently to begin the socializing process.

If your baby guineas need any more than that, your vet will be able to guide you every step of the way.

Baby guinea pig care

We hope you enjoyed reading about baby guinea pigs.

Although they are born almost fully developed, cute baby guinea pigs still undergo many changes as they reach adulthood.

Newborn baby guinea pigs need age-appropriate solid food from day one, which they consume alongside their mother’s milk.

Male and female baby guinea pigs should be separated by the time they’re a month old to avoid accidental pregnancies.

The first weeks of life are an important time to get a baby guinea pig used to being handled, before they go home with their new owner.

Have you raised baby guineas?

What were the highlights?

We’d love to hear about your experiences in the comment section below!



Bartesaghi, R., Severi, S., Effects of early environment on field CA2 pyramidal neurons in the guinea-pig, Neuroscience, 2004

Briscoe, T.A., et al, Cardiovascular and renal disease in the adolescent guinea pig after chronic placental insufficiency, American Journal of Obstetrics and Gynecology, 2004

Dwyer, C.M., et al, The effect of maternal undernutrition on the growth and development of the guinea pig placenta, Journal of Developmental Physiology, 1992

Kind, K.L., Chronic maternal feed restriction impairs growth but increases adiposity of the fetal guinea pig, American Journal of Physiology, Regulatory, Integrative and Comparative Physiology, 2005


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