What is the earliest age a dog can get theri period?

A female dog can typically experience her first heat cycle, or "period," as early as six months of age, although it can vary by breed and individual development. Smaller breeds may start their heat as early as four months, while larger breeds might not begin until they are over a year old. The heat cycle occurs approximately every six months, lasting about two to three weeks. It's important for dog owners to be aware of this developmental stage for responsible care and management.