How to determine the age of a guinea pig?

How old can your guinea pigs be? If you bought them from a pet store, this data can be very questionable: you cannot trust the information given to you because the sellers are not specialists and they do not know anything about the origin of the animals. Also, even if you are told that the guinea pig is 3 months old, the minimum age to be sold, it may actually be less. Also, here are some elements that can help you assess the age of your guinea pigs, without acquiring any certainty.

What the guinea pig’s weight can tell you

A healthy animal sees its growth associated with weight curve within limits which are well known. Regardless of weight, a healthy guinea pig has an intact coat that is as shiny as its eyes. Her eyelids don’t stick together and her anus isn’t dirty.

A sick animal, poorly weaned, or suffering from inbreeding problems lying outside the curve, it is impossible, without knowing its date of birth, to determine its age.

We can only recommend that you buy your animals from breeders. These breed guinea pigs without threatening their health, by separating individuals at the right time to avoid uncontrolled breeding, and by selecting the most beautiful individuals. Their tracking allows them to tell you the date of birth of the animals.

The weight curve of the guinea pig from birth to adulthood

The birth weight of a guinea pig is between 50 and 100 g. This range is wide because the weight depends on the number of cubs in the litter. A baby guinea pig usually has 3 siblings, but the mother can give birth to up to 6 pups. However, the weight of the little ones decreases as the births progress: the first born is bigger than the last.

The newly born baby guinea pig is ready to evolve independently if it becomes necessary. Well formed, covered with hair, equipped with claws, teeth and eyes wide open, he is able to run only a few hours after birth. It can also ingest solid food from the age of 2 days, some of them munching on hay within a few hours of being born. But their digestive system is not mature enough to process this food. It is therefore essential to spend the first 3 weeks of their life, fed with breastmilk.

At the end of a week of life, the small guinea pig can already weigh 150 g, and between 140 and 200 g after 2 weeks.
It can reach 240 g at the age of 3 weeks, the age of weaning, but most reach it around the age of one month. The growth of the guinea pig during these first weeks of life is impressive as its weight has tripled in the meantime. It is the age of 3 weeks or the weight of 300 g that constitute the minimum thresholds below which it is forbidden to sell a guinea pig.

The differences between the sexes take on importance from 3 months: a guinea pig weighs between 350 and 700 g. At 6 months, he weighs between 550 and 950 g, and at 8 months, he usually weighs between 650 g and over a kilo.

When the guinea pig reaches its final size and weight, a female weighs between 750 g and 1.2 kg while a male weighs between 800 g and 1.5 kg approximately.

Other benchmarks

By the age of one month, the shape of the ears may change. For the standards, they must fall and, if this is not the case, your guinea pig will not be able to be presented in competition. Note that in Shelties the modification may take a little longer than in others.

At 2 months, the fur of longhaired guinea pigs has not yet reached its final length. It is at 3 months that you can appreciate its final texture and length.

3 months, it is also the age of sexual maturity without this means that it is good for these animals to reproduce so early, especially for the females. Pregnancy is a stressful time for the body, so it is more respectful of the animal to wait until it has reached 4 to 5 months, or a weight of 750 g. The breeders also wait until the guinea pig is 4 months old because it is from this age that they can spot beautiful subjects and select them for breeding.

When the guinea pig is old

In captivity, these animals have a longevity of between 4 and 8 years. Females stop reproducing around the age of 3. The state of health varies a lot depending on your ability to take good care of your guinea pigs, but also their genetic predispositions. So if there are no characteristic and obvious signs of old age, 4 years mark the beginning of the 3rd age. The guinea pig is much calmer, without being inactive.

As the immune system weakens, it becomes more susceptible to disease: problems with the skin, respiratory, digestive and urinary systems may appear. Chewing can also become more difficult. The old guinea pig gradually loses weight and the spine is more and more visible.