There comes a time when every guinea parent needs to weigh their guinea pigs.
After all, performing the occasioning “weighing ceremony” is an essential part of caring for your guinea pig and one of the key indicators of their overall health.
Luckily, we’ve got all the answers for you right here. Within the next minute or so we’ll have you upto speed – and what may previously have seemed like something from the dark arts, will be as simple as you could ever imagine.
Average Guinea Pig Weight (What’s Normal and Healthy?)
Of course, every guinea pig is different. Just like humans, variations in individual genetics such as bone structure, muscle mass, fat distribution and breed will determine what a healthy weight looks like for your piggie.
Some will simply have a different “shape” to others. Let’s say, some are natural athletes, whereas others are more bookish types! According to Biology, Husbandry, and Clinical Techniques of Guinea Pigs, here are the generally accepted reference weight ranges:
- Average Weight (adult male): 900g – 1200g
- Average Weight (adult female): 700g – 900g
But don’t read too much into these… they are based simply on ‘average’ guinea pigs – i.e., they only cover 2 standard deviations from the mean.
It is totally possible your guinea pig could be a genetic outlayer and it’s natural, healthy weight could lay outside of these ranges. These ranges only cover about 98 out of 100 guinea pigs.
So use these ranges as a guide, but just as importantly, judge your guinea pig’s weight by sight and feel as well. If he is eating a healthy diet including lots of grass and hay and not too many pellets – as well as getting a decent amount of daily exercise and seems active and alert – then chances are he’s fine.
Guinea Pig Weight Chart
Guinea pigs tend to be fully grown at around 14 months old. So after this time, it will be easier to determine your guinea pig’s “normal” weight (i.e., biological set point). Growth is especially fast in the first 8 weeks and guinea pigs will generally double in weight over this time. Growth then tends to slow and the curve “flattens” a little.
The best chart of guinea pig ages by weight I could find was this one from the University of Hong Kong Faculty of Medicine:
Sadly the data only runs to 12 weeks, but I couldn’t find any other scientifically verifiable breed specific mean weight by age data taken from a decent sample size. There are a bunch of ad hoc reports and charts around the Internet, but nothing collected from a large enough sample to be valid.
How To Weigh A Guinea Pig
This is the easy part folks:
- Grab a guinea pig
- Grab a pair of digital kitchen scales (actually, you should probably grab these first, in case your piggie decides to embark on an impromptu leap of death from your hands)
- Pop a bowl containing a little grass or hay into the scales and zero them
- Place guinea pig in bowl
- Observe weight!
Well, this is the simple way of getting an accurate measurement of your guinea pig’s weight.
But there’s a more practical way of doing the same thing. And that’s with what we call the “rib test”. Check out this Guinea Pig Size O Meter to give you an idea.
Basically you want to be able to feel your guinea pig’s hips and spine – and even ribcage – with your finger. If you can’t feel them at all, your piggie is probably overweight. But on the other hand, they shouldn’t be too pronounced (as in feel really bony, with no covering off fat tissue at all) either – which could indicate an underweight issue.
How Often To Weigh?
Many sources recommend checking your guinea pig’s weight every week. Maybe it’s just me, but here at GuineaMates we consider that a little extreme. That means I’d be weighing my guinea babies more often than I weigh myself!
What we suggest is using more of a practical approach and simply keeping a good eye on your guinea pigs’s physical health every day.
This includes making sure their eyes are bright, their coats are shiny, their poos are in good condition and that they don’t appear to have experienced dramatic weight loss or gain.
But as well as a good eye, keep a good hand on it!
What I mean by this, is make sure your guinea pig feels OK every time you pick him up. Using the above “ribs” guide, you’ll soon get used to how your guinea pig feels when he is at a good weight.
Apart from that, we put our piggies on the scales every month or so, just to check that they are around the normal distribution for their age.
Weight Fluctuation – Maybe my piggie is sick?
Of course, the exception to all these guidelines is if your guinea pig is loosing weight dramatically. Fluctuations in weight are normal throughout the day (like all mammals) and throughout the week, but if your guinea pig has lost 100g or more (over any period of time) then this is a sign of a health issue and you should have your piggie checked by a vet right away.
As a general guide, guinea pig weight fluctuations fall within these guidelines:
- One ounce weight fluctuation is OK.
- Two ounces – Go on alert.
- Three ounces – Extreme red alert.
- Four ounces – Get the pig to a vet.
If you do establish that your guinea pig is sick and has been loosing weight, then it would be a good idea to weigh them daily until they are better – and weekly for a while after until they are fully recovered.
At the end of the day, you should care for your guinea pig just like any other member of your family!
Which means keeping an eye on their overall health, including their weight.
- A method of live weight evaluation for local guinea pigs (Cavia porcellus L.) of the western highlands of Cameroon: synthesis of linear body measurements
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