How Long Does a Dog Stay in Estrus?

A female dog's estrus, also known as her "heat," refers to her natural mating cycle. Just as female and male humans experience puberty, female dogs experience estrus at relatively the same point and for the same length of time, but this cycle can also vary between individual dogs. This cycle is divided into four separate stages with recognizable differences, helping you to understand the specific cycle and time frame your dog is experiencing.

  1. Proestrus

    • A female dog who is never spayed will experience vaginal bleeding; the owner will notice occasional spotting. The bleeding cycle lasts between four to nine days, according to the Talk to the Vet website. This stage can be deceiving because the female dog is not yet interested in male dogs although they express a strong interest in her.

    Estrus

    • During her estrus, a female dog is especially interested in male dogs. Left to their own devices, an intact male and female dog would almost surely mate at this stage. Rather than bleeding, the female dog releases yellow discharge. This typically lasts between four to 13 days. Test whether your female dog is in estrus by touching her back firmly. Her tail moves to the side, as if preparing for a male dog that has mounted her.

    Metestrus and Anestrus

    • Metestrus and anestrus are the last stages of this cycle and show no outward signs. Internally, your female dog is experiencing ovarian activity and may experience false pregnancies.

    The Complete Cycle

    • Your dog will most likely have her first estrus cycle between six to 12 months of age. The Talk to the Vet website notes that larger breeds may not have their first estrus until 12 to 24 months. A female's estrus will occur twice a year, taking a total of 6 months to end completely. When attempting to protect an intact female from mating, consider her in danger of becoming pregnant for a minimum of 21 days after the first signs of proestrus, or vaginal bleeding.