Female dogs who have not been spayed go into heat about twice a year, starting when they are about 6 to 15 months old. During heat, females are receptive to mating and release mating hormones.

Here's what to expect when your female dog comes into heat. When Should I Expect My Dog's First Heat? On average, most dogs will begin their first heat cycle between six and 15 months of age.

False pregnancy is a common condition in unneutered female dogs. It’s also known as pseudopregnancy, ... Depending on the breed, dogs go into heat 1-3 times per year. ...