In medicine, etiology refers to the many factors coming together to cause an illness. It is normally the focus of epidemiological studies. The etiology of scurvy is a good example. With scurvy, sailors going to sea often lacked fresh vegetables.
So, how long are dogs pregnant? The answer varies depending on several factors, but the average length of gestation, aka pregnancy, lasts between 58 to 67 days, with 63 days being the average delivery date.
Dogs are usually pregnant around 63 days, or 9 weeks. You should count from the first time she was bred, as the earliest due date. Then count from the last time she was bred for the latest due date. The range is from 58-65 days.