When do Miniature Bull Terriers stop growing?

Miniature Bull Terriers stop growing around 12 months old. While they will reach their full height around nine months old, Miniature Bull Terriers will continue to fill out and develop muscle until around their first birthday. 

Once they stop growing in height, you can transition them to adult dog food, which supports their long-term health. Make sure to slowly switch over their food over the course of a week to prevent gastrointestinal issues.