Puppies generally stop growing in height between 9 and 18 months of age, although this varies depending on their breed size.
- Small breeds (like Chihuahuas, Dachshunds, Pugs, and French Bulldogs) usually reach their adult size by 6 to 9 months. They may continue to fill out with muscle after that but won't grow taller.
- Medium breeds (such as Border Collies and Beagles) tend to stop growing between 9 months and 1 year, although they might still bulk up after that.
- Large breeds (like Golden Retrievers and Labradors) typically stop growing in height between 12 and 18 months but may continue to fill out until around 2 years old.
- Giant breeds (such as Great Danes and Saint Bernards) often keep growing until they are nearly 2 years old, sometimes up to 24 months.
Puppies stop growing when the growth plates in their long bones close, which usually corresponds with these age ranges. Even after they stop growing taller, dogs can still develop muscle and fat, "filling out" in build for some time afterward.
