Dog in Heat Symptoms

For an owner of an unspayed dog, the ability to identify signs and symptoms of her reproductive cycle will make it easier to plan for or prevent puppies. Each week of the cycle brings new symptoms and being aware of the changing cycle will help you know when to avoid male dogs or when it is time to breed.

    First Week: Proestrus

    • The proestrus phase of heat generally lasts about nine days. During this phase, you will notice some physical changes in your dog. Swelling of the vulva will vary from dog to dog, but a marked change will occur in every dog and can be visible both in the vulva itself and as a trail from the vulva to the opening just below the anus.

      Bloody discharge also varies from dog to dog, but bleeding will begin light and grow heavier toward midweek. Pads or diapers can be purchased to catch discharge during this time in your dog's cycle.

      A female's appetite may increase and personality changes, such as becoming more affectionate or clingy, may be noticeable during this time.

    Second Week: Estrus

    • During the second week of heat, or estrus, the female's ovaries release eggs, making her fertile. Discharge will become lighter and change from red to a lighter pink. The vulva begins to soften when the swelling subsides, allowing for mating. While your female may have tucked her tail during the first phase of heat, she now will begin waving it to help male dogs in the area catch her scent. As a male dog approaches she may turn her back side toward him, moving her tail out of the way to invite him to mount. This phase is where mating and pregnancy may occur.

    Third Week: Diestrus

    • Diestrus is the third phase of a dog's heat cycle. During this time, your dog is no longer fertile. Discharge will return to its original red color and will gradually decrease over the week until it stops altogether. The vulva also will gradually return to normal over the course of the week. Flirting ceases during this time, and your dog should return to her regular personality and eating habits. If a successful breeding occurred during the estrus phase, this is he beginning of the 63-day gestation period.

    Anestrus

    • If no pregnancy occurred during this heat cycle, your dog will go into anestrus, the resting time between cycles. Usually lasting from five to 11 months, this period varies greatly from dog to dog.

    Pregnancy

    • If your dog mated or was bred during her heat cycle, she may be pregnant. It is important to visit her vet to ensure she gets the best care.