Hi and welcome
The variation in guinea pig weights and sizes is much larger than most owners expect. As long as Badger is a healthy weight/size ratio in himself, then there is nothing to worry about.
Please do not try to overfeed to make him fit an arbitrary human box and concentrate on a good hay based long term diet instead - the latter is much more crucial for longevity than the first. Some of my piggies that touched the 800g only at the peak of their lives nevertheless beat many normal sized companions to live to 8 years even though they were rescued from some really bad places.
You may find these links here helpful.
This guide explains about the BMI and its importance for good health as well as learning how to put weight loss in its proper individual perspective and how to use the various monitoring methods most effectively.
1 Weight and Weight Loss
- Why regular weight monitoring matters
- How weight changes over a lifetime
- How to weigh on your kitchen scales (with video)
- The weight loss rules
- How critical is the weight loss for my piggy?
- Possible causes for weight loss
2 Body Mass Index (BMI) or 'Heft'
- Why is understanding your piggy's weight so important?
- 'Average' weight vs. individual weight - the big trip up
- How to check for the BMI
3 The...
Here is our diet guide. A good diet can add 1-2 years to a normal healthy life span and take it from the lower end to the upper.
1 The recommended ratio of food groups
2 Hay and fresh grass
3 Vegetables, fresh herbs and fruit with an illustrated balanced sample diet
4 Special dietary needs
- Urinary tract infections, bladder stones and sterile IC (non-bacterial interstitial cystitis)
- Diabetes and long term digestive problems
- Impaction in boars
- Pregnancy and nursing dietary tweaks (only visible to registered members who have accepted our no intentional breeding policy)...
A piggy won't reach adulthood until about 15 months and won't reach the peak of their lives (and natural weight) until about 2-3 years of age so Badger may crack the 800g but if he doesn't it won't matter as long as you give him a good and healthy life.