The first time you own a female Frenchie you should be aware that she will get into heat anywhere between 6 and 12 months of age. Occasionally dogs will enter this stage as late as 14 months but this is very rare. You can expect some changes in your furry friends behavior when she is in heat. You may notice her becoming more aggressive or clingy. At this point she may want to be petted more.
Bulldogs usually get into heat twice a year but some go through an extra cycle which is fine. Occasionally your bitch might miss a season as she gets older. Frenchies however remain fertile throughout their lives. Humans do not go through a menopausal stage like them. As a result your dog can get pregnant at any age.
In addition as bitches get older they may enter a period known as a silent season' during which they will not show any external or behavioral signs that they are actually in heat. It does not mean however that they can not get pregnant as we have explained above.