It depends on which species your chinchilla belongs to. If it is an American chinchilla, it may grow longer. Generally, it will be completely finalized by 10 months. If it is found after 10 months, The body shape is larger than before, which can only mean that it has gained weight and eaten well, but its bones have been completely formed.

Chinchillas imported from Europe, the Netherlands, Hong Kong and other places are fully formed in 8 months.