how often do dogs go on heat

Dogs typically go into heat about twice a year , roughly every 6 months. However, the exact frequency varies depending on the dog's breed, size, and age. Smaller dogs tend to go into heat more frequently—sometimes three times a year—while very large breeds may only have one heat cycle per year. The heat cycle usually lasts about 18 to 21 days. Dogs can experience their first heat anywhere from 6 months to 2 years old, with smaller breeds generally starting earlier and larger breeds later. As they age, the time between heat cycles may increase, but they do not experience menopause like humans and can continue cycling throughout their lives unless spayed.