Today I've weighted my chinchillas and while Kina, 4yo, is in the normal range weighting 595 g, Casper is worrying me with just 386g... He's 2yo and he's Speedy Gonzales, chinchilla version, he just can't stand still and he's never been big. I'm checking his teeth weekly, his poopoo and how & how much he eats to see if there are any changes and everything's been ok. As treats he only gets goji berries/rose hips/ raisins but only once in a few months or on special occasions. I've been giving him porridge oats but again, in small amounts. Their diet is based on hay and Versele laga chinchilla food ( i live in Romania and it's the best food i've found around here) which they enjoy.
So what I'm asking is since his health is ok, he's never been heavy and he's eating alright ( please let me know if you advice against the type of food i'm giving them ) should I be worried about his weight and if so, what can I do to help him gain some?
I've attached a photo of him.
Thanks in advance!