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.
Average pregnancy duration. The duration of a dogâs pregnancy may vary depending on a few factors. But the average duration of pregnancy for a dog is normally lasts for 58 days to 67days. The probable delivery date will be 63rd day from the date of breeding.