Essentia
Jax Chinchilla Rescue
The last time I was at the vet with a chin, I took a 500g white sapphire with a UTI in so I could get some antibiotics for him. The vet kept calling him such a "big guy". I questioned him about it, and he genuinely thought it was a large chin.
When I took my 850g rescue into the vet they believed he was overweight. I explained to them that he is just a larger chin, as he really didn't have many rolls and such, and that when a chin is on a good quality pellet and hay it's difficult to have an overweight chin. I doubt they believed me, but you know how that goes. I think they mainly see the 450g chins that are purchased from pet stores and backyard breeders so when they see one more than that they feel they have to question it. If only they got to see the well bred chinchillas more often. Their minds would be blown.