Although it seems that animals maintain their breeding instincts, this is not always the case. If a problem develops, such as a uterine infection, a difficult pregnancy, or difficulties giving delivery, they may need assistance from their human caregivers. Learn about the four phases of your dog’s heat cycle to be prepared for any problems.

What Are the Four Stages of the Canine Heat Cycle?

Your dog will go through four stages throughout her whole heat cycle. A normal estrus period lasts two to four weeks, followed by a pregnancy or resting phase. Knowing what to anticipate can help you and your dog prepare for any unusual actions or issues that may arise during her heat cycle. You’ll observe these four phases as your dog goes through her cycle: 

Proestrus: Proestrus is the start of the heat phase, during which your dog’s body prepares to mate. It lasts approximately nine days on average but may last anywhere from three to seventeen days. Her vulva may enlarge and a blood-tinged discharge may appear, although many dogs are meticulous about messes and will clean themselves up before you notice. Your dog may also exhibit clinging behaviour by keeping her tail close to her body and sticking to your side. Your dog will attract men at this stage of the heat cycle, but she will not be receptive to them and may turn hostile if they try to mount her.

Estrus: The estrus phase, also known as the mating period, lasts around nine days on average, although it may last as little as three days or as long as 21 days. Blood flow will slow and eventually cease at this period, although the discharge may become straw-coloured. Male dogs will attract and accept female dogs, and ovulation will occur two to three days after mating. Your dog may be urinating more often and marking areas inside and outside your house to distribute pheromone signals signalling her desire to procreate. If there is an intact male available, your female dog will most likely approach him with her hindquarters first and her tail tucked to the side.

Diestrus: This phase follows the “in heat” stage and lasts about two months. As her vulva recovers to normal size and the vaginal discharge evaporate, her body will either continue the pregnancy or rest.

Anestrus: Anestrus is the uterine repair stage, during which there is no sexual or hormonal activity, and may continue anywhere from 90 to 150 days until the next proestrus stage starts.

How to Keep Your Dog From Going into Heat 

Unless you want to improve the breed, spaying is strongly advised for all female dogs. Spaying your dog reduces her chance of mammary cancer and prevents her from contracting uterine infections or going through a heat cycle.

Spaying your dog reduces her chance of mammary cancer and prevents her from contracting uterine infections or going through a heat cycle. Consult your veterinarian to determine the ideal time to spay or neuter your pet.

Important Information About Dog Heat Cycle

The age at which a dog experiences her first estrus varies significantly across breeds. Here are some general “rules of thumb” regarding your dog’s heat cycle. Toy and tiny breeds develop considerably faster than large breeds, and they may get pregnant as young as four months old. Giant breeds may not have their first heat until they are two years old.

A female dog’s first heat occurs between the ages of six and fifteen months.

Every year, most dogs have two oestrous cycles.

Male dogs will be drawn to a female dog that is beginning her heat cycle before she is ready to breed. Keep an eye out for defensive aggressiveness, which serves as a warning to males to back off.

Remember that just because your dog isn’t bleeding anymore doesn’t mean she can’t become pregnant. She’ll be much more willing to allow a guy mate once the bloody discharge ends.

Dogs may get pregnant during their first heat cycle, but this is not recommended since a six-month-old dog is not completely developed, and problems for both the mother and the pups are more probable.

Before being bred, a female dog should go through two regular heat cycles.

Keep your dog away from male dogs for at least three to four weeks after the first indication of bleeding to avoid a potential pregnancy when she is in heat.