The term "in season" refers to the days when an unaltered female dog experiences menstrual flow and fertility. The cycle lasts about twenty-one days, with days seven to fifteen being the time when the dog is most fertile. The cycle is easy to remember as seven days coming into heat, seven days in heat and seven days going out, but these are only estimations, and pregnancy can occur at any time if the conditions are right.
Hormonal urges are a powerful force
Watch for symptoms of heat. The female may begin to lick at her vulva more frequently. You may notice a discharge of blood or a more yellowish fluid and a swelling of the vulva. The female may stand still and move her tail aside if her back is touched. She may mount other dogs or objects. She may act more friendly toward other dogs, present herself to them and allow other dogs to mount her.
Confine your female. Extra care should be taken to isolate your dog from male dogs during this time as she is both very fertile and open to accepting the sexual attention of males. Male dogs have performed amazing feats to gain access to a female in heat, and females have shown themselves equally ingenious at escaping confinement to hook up with a male. Normal restraints and fences may not be sufficient to keep away suitors and your female may actively seek out males during this time.
Protect your carpets or furniture from bloodstains and discharge by discouraging the dog from using them. An alternative solution is to put a pad or old towel between the dog and any surfaces that could be stained. A female dog typically begins this cycle at approximately six months of age, but this varies widely in individual animals and it may not begin until almost age two. The cycle then repeats, usually at regular intervals of six months. This varies with each animal, but most dogs have regular cycles that you can plan for.
Think twice before you breed your animal. Unaltered animals contribute to the overcrowding of animal shelters and the euthanizing of millions of unwanted animals every year in the United States. Poor reasons for breeding include the idea that having a litter will calm a dog or end false pregnancies. If the choice is made to breed, the male and female should be placed together several times during the receptive portion of her cycle to ensure that coupling is successful. Puppies can be expected approximately sixty days after successful breeding.
Watch for interruptions in a dog's normal cycle. These may indicate a medical problem and should be investigated by a veterinarian.
Discuss with your vet the best time to consider spaying the female so unwanted litters of puppies do not result. With spaying, there are none of the hassles or behaviors associated with false pregnancy, there is no worry about unplanned litters, and there are some benefits to the dog's long-term health by spaying her within the first two years of her life.