The gestation period of dogs is usually calculated as 60 days (the physiological range is 59-68 days). There are four main possible reasons for the prolonged gestation period of female dogs: false pregnancy; inaccurate mating date records; repeated mating; single pregnancy. The real pathological prolonged pregnancy usually occurs in single pregnancy. If the gestation period of the female dog has reached 69 days, but there are no abnormal clinical symptoms, there is generally no need for human intervention. If oxytocin is used before the female dog begins to give birth, it will lead to human accidents. In most cases, spontaneous delivery will occur within a few days. However, if the fetus is over-mature, its chance of survival will decrease. The longer the gestation period, the greater the risk of dystocia. At this time, veterinary X-rays and animal B-ultrasound examinations are required to determine whether the delivery process can proceed smoothly. If it is confirmed to be a single pregnancy and it is proved that the size of the fetus can pass through the pelvic inlet, artificial induction measures can be taken even if the female dog has no signs of delivery. Prostaglandins can be used.

If the dog's owner thinks that there is a problem with the dog's delivery, the first thing to find out is whether the female dog has really entered the delivery state. In addition to the main complaint and the whole body examination, the decisive criteria for judgment are mainly vaginal examination. The examination content includes the width of the vagina in the pelvic area, the relaxation of the vaginal wall, the moisture of the vagina and the lubricity of the vaginal mucosa. If necessary, check the symmetry of the pelvis and whether there is stenosis. When doing vaginal examination, sometimes the fingertips can feel the fetus or the top of the fetal sac. If the cause of dystocia cannot be found, you can use your other hand to hold up the abdomen of the female dog. When the fetus is already at the entrance of the pelvis, in most cases you can feel the fetus with your fingers and even determine whether there is an abnormality in the fetal direction. After the finger is inserted into the vagina of the female dog, it will reflexively cause the female dog's uterine contraction and straining, pushing the fetus to the pelvic opening, and also help the finger approach the fetus. At the same time, whether the straining is strong or not can help determine whether the cause of dystocia is caused by the fetus or the female dog. If the above methods still cannot find the cause of dystocia, it is recommended to use a canine vaginal speculum to observe the opening of the cervix and the fetal sac of large female dogs, because it is difficult to use fingers to check the above contents in large female dogs. If necessary, abdominal veterinary X-ray examination or animal B-ultrasound examination can be used for judgment, but veterinary X-ray or animal B-ultrasound examination has certain technical requirements, otherwise it is easy to make a wrong judgment.