Do Hormones Induce Puppy Birth

Who hasn't asked themselves this question? If the answer is no then what does? Well, at a given moment, the uterus, which has until then seemed to be satisfied with its content, starts to object and reject what it has inside; and the uterine neck, which has until that moment remained closed, opens up, becoming soft and dilating in order to allow the expelling of the puppies. The Levels of progesterone moderately go up in the days prior to birth and a couple of hours (approximately 24 hours) before contraction starts, they suddenly go down, although it still is not clear up to what pints this descent is determining; however, we know that progesterone is indispensable for containing the continuity of the bitch's pregnancy.

Besides, it has been confirmed that corticosteroids significantly increase during a 24 hours prior to birth, at the same rate that the levels of progesterone go down, although we don't know where or how that happens. Lastly, the hours before the birth also coincide with a certain increase of the levels of estradiol. This is not the same in other mammals, though. However it is and coinciding with a sudden drop of the levels of progesterone, there is a drop in the body temperature, sometimes below 37.5° Celsius. Therefore, a practical and reliable way to know if the moment of birth is around the corner is to control the body temperature of the bitch, around the 58 day of pregnancy every three hours.