A dog's heat cycle, also known as oestrus, lasts anywhere from five to nine days and occurs twice a year, according to Colorado veterinarian Bari L. Speilman. During this time, the dog has small amounts of bloody discharge around her vagina, as well as swollen vulvar lips. Along with the physical effects, there are some behavioural signs to watch out for when a dog is in heat.
A female dog in heat often shows signs of restlessness and anxiety, according to VetInfo.com. Another behaviour a dog in heat might show is frequent urination, according to Dr. Spielman. The increased urination is the dog's way of marking her territory with her scent so male dogs can find her.
Anxiety and restlessness are the main behavioural symptoms of a dog in heat. Comforting the dog during this period helps relieve her anxiety, VetInfo.com says. Speaking in a soothing tone helps her relax, as does extra grooming, petting, scratching or massaging. Buying a special treat such as a new toy or a large, juicy bone can also help relieve anxiety and help the dog relax.
There are several ways to prevent the behaviour that comes with the canine heat cycle by stopping the dog from going into heat, including spaying, birth control pills, liquid contraceptives and a contraceptive implant, according to VetInfo.com. Spaying is a surgical procedure that removes the uterus and ovaries in a female dog, making her incapable of reproducing. Organizations such as the American Kennel Club recommend spaying for dogs not meant to breed. Spaying removes the risk of breast and reproductive system cancers, but may cause joint problems, obesity and thyroid disease. The birth control pill delays the dog's heat cycle but has side effects such as breast cancer, weight gain and skin problems. Liquid contraceptives given 30 days prior to the beginning of the heat cycle prevent pregnancy, and side effects include liver damage, behavioural changes, rashes and vaginal distortion. The contraceptive implant suppresses hormones in female dogs. A veterinarian places the implant under the dog's skin between the shoulder blades, and the implant is effective for six months.
The attention of many males vying for the attention of a dog in heat can be overwhelming and can actually make the female dog feel more anxious, according to VetInfo.com. Keeping her away from any male dogs, especially those who are not neutered, helps keep her anxiety at a minimum.
A male dog can smell a female dog in heat from up to five miles away, according to the American Kennel Club. If the female dog is outdoors, males will smell her much sooner, especially if she is urinating to spray her scent. To prevent an unwanted pregnancy, the American Kennel Club recommends containing the dog during her heat cycle.