Are my guinea pigs underweight?

[Avey1]

I recently bought 2 male guinea pigs (Short haired American) around a month ago and they are now 14 weeks old.
I have had no problems with them and they seem healthy and are both eating the recommended amount of fresh food, pellets and hay.
I just weighed them for the first time and my male guinea pigs Bert weighed 718 grams and the other Ernie weighted 704 grams.
I read That the recommended weight should be between 900g and 1200g.
They don’t look underweight in my opinion and you can’t see their ribs or really feel them, but should I be worried or start feeding them more?

 

[Piggies&buns]

The 900-1200g weight you quote is more of an adult weight - your piggies wont be at that weight until much later.
However, there is also no recommended weight because they all have their own genetically predetermined adult weight. For example, anything from 800-1600g is within normal adult range but that doesn’t mean to say a piggy slightly less of a piggy slightly more than that range isn’t healthy.

What is important at their age is that they gain weight well each well.
Their diet should be unlimited amounts of hay, one cup of veg each and one tablespoon of pellets each. Hay is the most important part of their diet.

As there is such a wide range of weights, it means weight is not a good way to determine what is healthy for an individual piggy, their heft is.
You check their heft by placing your hands around their ribs. You should be able to feel their ribs with a nice fat layer on them.

The guides below explain

Long Term Balanced General And Special Needs Guinea Pig Diets
Weight - Monitoring and Management

 

[Wiebke]

I recently bought 2 male guinea pigs (Short haired American) around a month ago and they are now 14 weeks old.
I have had no problems with them and they seem healthy and are both eating the recommended amount of fresh food, pellets and hay.
I just weighed them for the first time and my male guinea pigs Bert weighed 718 grams and the other Ernie weighted 704 grams.
I read That the recommended weight should be between 900g and 1200g.
They don’t look underweight in my opinion and you can’t see their ribs or really feel them, but should I be worried or start feeding them more?

Hi!

You have got two piggies on the verge of becoming teenagers; and they are a very good weight for that. You do not expect them to be an adult for a while yet (not before ca. 15 months).

Can I also please point out that while 900-1200g is generally seen as an ideal weight it does in no way mean that any other weight is not good? I've had piggies that were bordering on underweight at 1400g and those that were overweight at 800g. The human weight recommendation basically declares half of the perfectly healthy 'non-standard' adults as deficient; which I find personally a very troubling concept.

It is much better to check the ribcage as to whether you can just about feel them but not feel every single one or not be able to feel any ribs at all ('feeling for the heft'). This is a much more reliable measure as to whether your piggies are a healthy weight for their current size or not. Ultimately, it doesn't matter what individual weight your piggies are as long as they are a good weight/health ratio and as long as they are on a life prolonging and health boosting hay/grass fibre hay (and not veg/pellet) based diet to live a hopefully good life span. A good diet can add 1-2 years to a healthy piggy's life and take them from the lower end of the average age to the upper and even beyond.

Please take the time to read these two information guides here. They are the crucial ones that will help you in setting your piggies on a good course:
Weight - Monitoring and Management
Long Term Balanced General And Special Needs Guinea Pig Diets

These guides are an important part of our much more extense practical and helpful New Owners information resource, which you may find very helpful in all sorts of respects. You may want to bookmark the link, browse, read and re-read at need because in some guides you will pick up on different things at difference stages of experience.
Getting Started - New Owners' Most Helpful Guides