When do Chinooks stop growing?

Chinooks typically stop growing between 18 and 24 months. While they reach most of their height by around their first birthday, they can continue to fill out and develop muscle until they’re 18 to 24 months old, depending on their genetics and diet. 

You can switch them to adult food when they reach about 12 months old as their dietary needs shift away from rapid growth. To ease the transition and prevent GI upset, slowly add the new adult food into their puppy food over the course of a week until they’re fully switched over.