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Comprehensive Guide to the Canine Heat Cycle

Understanding your female dog's heat cycle is crucial for effective breeding management. This guide provides a detailed overview of the heat cycle stages, how to track them, and tips for managing and optimizing breeding success.

The Heat Cycle Stages in Dogs

A dog's heat cycle is divided into four stages:

  1. Proestrus (Coming In): This stage lasts about 7-10 days. During this period, the female's vulva swells, and she has a bloody discharge. She attracts males but is not yet receptive to mating.

  2. Estrus (Standing Heat): Lasting 5-10 days, this is when the female is receptive to mating. Ovulation occurs during this stage, and it is the optimal time for breeding.Canine Heat Cycle

  3. Diestrus (Going Out): This stage follows estrus and lasts about 60-90 days. If the female is pregnant, this is when gestation occurs. If she is not pregnant, her body will gradually return to normal.

  4. Anestrus (Between Cycles): This is the period of sexual inactivity between cycles, lasting about 3-4 months.

Tracking and Testing for the Canine Heat Cycle

Monitoring Behavioral Signs:

  • Watching for changes in behavior can provide clues about the heat cycle. Increased urination, nervousness, and a swollen vulva are indicators of proestrus. During estrus, the female will stand still and allow males to mount.

Vaginal Cytology and Progesterone Testing: Canine Heat Cycle

  • Vaginal Cytology: A simple swab test performed by a veterinarian can help determine the stage of the heat cycle.

  • Progesterone Testing: Blood tests measuring progesterone levels can accurately predict ovulation. Progesterone levels rise as the dog approaches ovulation:

  • <3 ng/ml: Proestrus

  • 4-10 ng/ml: Ovulation

  • 10-30 ng/ml: Fertile period

  • 35 ng/ml: Past the fertile period

LH Testing:

  • Luteinizing hormone (LH) testing detects the surge that precedes ovulation by 48 hours. This test is especially useful when using shipped semen.

Managing Breeding Timing

Optimal Breeding Timing:

  • For natural breeding, it is best to mate the dog every other day during estrus until she no longer stands for the male.

  • For artificial insemination, timing depends on the type of semen used:

  • Fresh or chilled semen: Breed once progesterone exceeds 5 ng/ml.

  • Frozen semen: Breed three days post-ovulation, once progesterone exceeds 20 ng/ml.

Sperm Viability:

  • Natural insemination sperm can live up to five days.

  • Artificial insemination sperm viability ranges from two days for chilled semen to one day for frozen semen.

Importance of Nutritional Supplements

Vitamin Deficiencies:

  • B Vitamins: Deficiencies can lead to delayed or irregular heat cycles.

  • Thiamine (B-1): A deficiency can cause the female to be reluctant to stand for mating.

  • Folic Acid: Essential for pheromone production and preventing birth defects.

  • Iron: Important during pregnancy for the development of red blood cells.

Recommended Supplements:

  • Breeder’s Edge® B Strong: A liquid vitamin supplement that includes all B vitamins and folic acid.

  • Breeder’s Edge® In Between For Her: A multivitamin that supports overall reproductive health.

  • Breeder’s Edge® Oxy Momma™: Supports nursing and recovery after whelping.

Managing and Triggering Heat Cycles

Natural Cycle Management:

  • Manipulating hormones to trigger heat cycles can be stressful for the dog and is not always effective. It is better to address any nutritional deficiencies and allow the dog to cycle naturally.

Breeding Strategy:

  • Breed your female at every heat cycle once she becomes fertile. Skipping cycles does not benefit the uterus and may lead to anestrus, delaying future heat cycles.

Retirement Age:

  • Females typically peak in fertility around age five. It is recommended to retire a female from breeding around age six, as older dogs are less consistent and more prone to complications.

Preventing Unwanted Pregnancies


  • Always supervise your female when she is in heat. Even brief interactions with a male dog can result in an unwanted pregnancy.

Protective Measures:

  • Use physical barriers like crates or pens to keep males and females apart. Remember, heat cycle panties are not effective at preventing mating; they only manage discharge.


Managing your female dog’s heat cycle effectively involves understanding the stages, using appropriate tests to determine the optimal breeding time, addressing nutritional needs, and ensuring proper supervision. By following these guidelines, you can optimize breeding success and maintain the health of your female dog.

For more detailed information and high-quality products to support canine reproductive health, visit or call us at 800-658-5308. We are dedicated to helping you ensure the health and success of your breeding program through expert advice and top-quality products.

dog heat cycle chart
dog heat cycle chart


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