Canine Menstruation: What Is It?

Canine menstruation, also known as a heat cycle or estrus, is a reproductive process that female dogs go through. It is the time when a female dog is fertile and can become pregnant. During this process, the dog’s body undergoes hormonal changes that prepare it for reproduction. These changes also affect the dog’s behavior, which can be challenging for owners to manage.

The Phases of a Dog’s Heat Cycle

A dog’s heat cycle consists of four phases: proestrus, estrus, diestrus, and anestrus. Proestrus is the phase before ovulation, and it lasts around nine days. During this time, the dog’s vulva swells, and there may be some discharge. Estrus is the phase when ovulation occurs, and it lasts around nine days. This is the phase when the dog is most fertile and receptive to males. Diestrus is the phase after ovulation, and it lasts around 60 days. If the dog does not become pregnant, she will go into anestrus, which is the phase of inactivity that lasts around three to four months.