how long do dogs grow?
Dogs typically grow until 1-2 years of age, with the duration largely dependent on their breed size, reaching most of their height within the first year.
- 1Small dog breeds generally reach their full adult size between 6 to 12 months of age.
- 2Medium dog breeds typically complete their skeletal growth by 12 to 15 months.
- 3Large and giant dog breeds can continue growing, particularly filling out with muscle mass, until 18 to 24 months of age.
- 4Growth plates, responsible for bone lengthening, usually close between 12-18 months, signaling the end of vertical growth.
Detailed Answer
The duration of a dog's growth period varies significantly based on its breed size. Small breeds, such as Chihuahuas or Miniature Poodles, mature quickly, often reaching their full adult height and weight between 6 to 12 months of age. Medium-sized breeds like Beagles or Border Collies generally complete their skeletal growth by 12 to 15 months.
Large and giant breeds, including German Shepherds, Golden Retrievers, and Great Danes, have the longest growth periods. While they may achieve much of their height by 12-18 months, they often continue to "fill out" and gain muscle mass until 18-24 months of age, or even slightly longer for some giant breeds. This extended growth period is due to their slower maturation rate and the need to develop a larger skeletal and muscular structure.
Skeletal growth occurs at epiphyseal plates (growth plates) at the ends of long bones. These plates gradually close and harden as the dog matures, typically between 12-18 months, signaling the end of bone lengthening. Proper nutrition is critical during these growth phases to support healthy bone and muscle development.
Warning: Avoid excessive high-impact exercise in puppies, especially large breeds, until their growth plates have closed. Overexertion can lead to orthopedic issues. Consult your veterinarian if you have concerns about your dog's growth rate or development.
Published: September 5, 2026