Hi there - I recently adopted a young guinea pig from a family who were not able to take care of him and wanted to pass him on. They didn't know exactly how old he is, but said they think 'almost a year old'. He's tiny though and only weighs about 600g, despite not seeming unwell or malnourished - he actually has a fairly round tummy. I'm just wondering if that's a normal weight for a 1 year old, or if it's likely that actually he's a bit younger? My previous guinea pigs I remember being pretty much fully grown at 1 year, but they are also pretty large as guineas go, so I'm not sure if they're good models. The new little one is a Texel, if that makes any difference. Thanks!
P.S. Have attached a photo in which you can see how young he looks.
View attachment 205033
Hi
What a little cutie!
The range of individual weights is much larger than you may expect. Some piggies may only grow as much as 700-800g as adults and still live a perfectly normal life span while others are actually bordering on underweight at 1500g.
Then there are the runts who - because of their genetic inheritance - will never grow large. I currently have two 10 months old rescue-born cousins, one just touching 600g and the other still stuck on 575g; they were small as babies and have both stopped pretty much growing at about 5 months old. In their case, it is highly likely that there is a genetic issue in play.
You cannot judge whether your piggy is a good weight/size ratio (BMI or heft) by looking at the belly/back end because the shape is breed related. You feel for it around the ribcage. As long as you can just about feel the ribs, your piggy is fine - whatever the age, weight, gender or body shape. 'Average' weight is an entirely human concept that leaves 50% of all healthy piggies arbitrarily outside the norm even though there is nothing wrong with them whatsoever!
Our Weight guide has more detailed information on how to judge whether a piggy is a good weight, over- or underweight, and what to do. It also contains practical advice on what to look out for during the weekly life-long health monitoring weigh-in and body check:
Weight - Monitoring and Management
The best thing you can is concentrate on a health, mainly grass hay/fresh grass based diet (hay and carefully introduced fresh, dog pee free grass) should make at least three quarters of what your piggy eats in a day.
Don't be tempted to supplement with calorific fillers or spoil your piggy with lots of treats - they are both essentially life shortening. In my own long term experience, it is a good simple diet with just 1 tablespoon of pellets per piggy per day and only a modicum of preferably green veg (these two food groups only replace the supplementary role of wild forage, of which rich root veg like carrots, grain and fruits would not have been a normal part of). Turn feeding time itself into fun time with enrichment instead of falling into the treat trap and focus on variety hay or herbage for treats; that is much better for both of you!
Here is our detailed diet guide:
Long Term Balanced General And Special Needs Guinea Pig Diets
I would however strongly recommend to have your little one thoroughly health checked by a vet, including for dental overgrowth in the grinding molars, in case there is an issue because of an inappropriate diet (lack of hay/grass - it is the very abrasive silica in them that guinea pig tooth growth has evolved agains) or malocclusion.
PS: I have had rescue adoptees from really bad backgrounds live a normal or even long life span if there were no bad genes in play due to indiscriminate breeding. My Teggy died 10 days ago aged 6 years despite her being surrendered to rescue with severe scurvy and dental overgrowth as a 400g 1 year old due to a (not vitamin C reinforced soft rabbit pellets only diet - her even smaller companion sadly didn't make it).
Please take the time to read the links in my post; they can really make a big difference for your piggy's health and longevity, as much as you can influence that.
